Lissencephaly spectrum disorders are a genetically heterogeneous group of malformations of cortical development characterized by abnormal cortical folding (reduced gyrification) due chiefly to impaired neuronal migration and disordered cortical lamination during embryonic development. The spectrum ranges from agyria (near-absent gyri) and pachygyria (broad, reduced gyri) to subcortical band heterotopia (SBH, "double cortex"). Most affected individuals present congenitally with a structural brain malformation and develop early intellectual disability, hypotonia, and drug-resistant seizures. Causal genes include PAFAH1B1 (LIS1), DCX, TUBA1A, ARX, RELN, DYNC1H1 and TUBG1, among others, with classic, X-linked, tubulinopathy, ARX-related, RELN-related and cobblestone (glycosylation-pathway) forms.
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name: Lissencephaly Spectrum Disorders
creation_date: "2026-06-03T00:00:00Z"
category: Mendelian
disease_term:
preferred_term: lissencephaly spectrum disorders
term:
id: MONDO:0018838
label: lissencephaly spectrum disorders
description: >-
Lissencephaly spectrum disorders are a genetically heterogeneous group of
malformations of cortical development characterized by abnormal cortical
folding (reduced gyrification) due chiefly to impaired neuronal migration and
disordered cortical lamination during embryonic development. The spectrum
ranges from agyria (near-absent gyri) and pachygyria (broad, reduced gyri) to
subcortical band heterotopia (SBH, "double cortex"). Most affected individuals
present congenitally with a structural brain malformation and develop early
intellectual disability, hypotonia, and drug-resistant seizures. Causal genes
include PAFAH1B1 (LIS1), DCX, TUBA1A, ARX, RELN, DYNC1H1 and TUBG1, among
others, with classic, X-linked, tubulinopathy, ARX-related, RELN-related and
cobblestone (glycosylation-pathway) forms.
notes: >-
Issue 4080 narrows this enrichment to the PAFAH1B1/LIS1 and DCX classical
LIS/SBH microtubule-dynein core. Miller-Dieker syndrome is handled as a
separate contiguous 17p13.3 deletion entry because YWHAE co-deletion and the
broader deletion phenotype are not equivalent to isolated PAFAH1B1 disease.
parents:
- congenital nervous system disorder
- disorder of development or morphogenesis
- hereditary neurological disease
references:
- reference: PMID:20301752
title: "PAFAH1B1-Related Lissencephaly / Subcortical Band Heterotopia."
tags:
- GeneReviews
- reference: PMID:20301364
title: "DCX-Related Disorders."
tags:
- GeneReviews
- reference: PMID:27010057
title: "Tubulinopathies Overview."
tags:
- GeneReviews
pathophysiology:
- name: Impaired Neuronal Migration
description: >-
Pathogenic variants in genes governing cytoskeletal dynamics and neuronal
migration disrupt the long-range radial migration of postmitotic cortical
neurons from the proliferative ventricular zone to their final laminar
position. The resulting failure or delay of migration produces a thickened,
smooth (agyric/pachygyric) cortex with disordered six-layered lamination.
cell_types:
- preferred_term: migrating cortical neuron
term:
id: CL:0000540
label: neuron
- preferred_term: radial glial progenitor
term:
id: CL:0000681
label: radial glial cell
biological_processes:
- preferred_term: radial neuronal migration in cerebral cortex
term:
id: GO:0021799
label: cerebral cortex radially oriented cell migration
modifier: DECREASED
- preferred_term: neuron migration
term:
id: GO:0001764
label: neuron migration
modifier: DECREASED
evidence:
- reference: PMID:10973257
reference_title: Autosomal recessive lissencephaly with cerebellar hypoplasia is associated with human RELN mutations.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
Lissencephaly ("smooth brain," from "lissos," meaning smooth, and
"encephalos," meaning brain) is a severe developmental disorder in
which neuronal migration is impaired, leading to a thickened cerebral
cortex whose normally folded contour is simplified and smooth.
explanation: >-
Establishes impaired neuronal migration as the core mechanism
producing the thickened, smooth cortex that defines the lissencephaly
spectrum.
- reference: PMID:23495356
reference_title: 'Cytoskeleton in action: lissencephaly, a neuronal migration disorder.'
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
Failure or delay in neuronal migration causes severe abnormalities in
cortical layering, which consequently results in human lissencephaly
('smooth brain'), a neuronal migration disorder.
explanation: >-
Directly links failure/delay of neuronal migration to the abnormal
cortical lamination that characterizes lissencephaly.
- name: Cytoskeletal and Microtubule Dysfunction
conforms_to: "microtubule_dependent_neuronal_migration_failure#Microtubule Apparatus Perturbation"
description: >-
Neuronal migration depends on microtubule and actin cytoskeletal dynamics
and on the dynein motor and its regulators. Mutations in microtubule
subunits (tubulins) and in microtubule/dynein-associated proteins such as
PAFAH1B1 (LIS1) and DCX impair microtubule organization, transport and
nucleokinesis, the coupling of the nucleus to the centrosome that drives
forward movement of migrating neurons.
cell_types:
- preferred_term: migrating cortical neuron
term:
id: CL:0000540
label: neuron
biological_processes:
- preferred_term: microtubule-based movement
term:
id: GO:0007018
label: microtubule-based movement
modifier: ABNORMAL
- preferred_term: nucleokinesis during radial migration
term:
id: GO:0021817
label: nucleokinesis involved in cell motility in cerebral cortex radial glia guided migration
modifier: ABNORMAL
evidence:
- reference: PMID:23495356
reference_title: 'Cytoskeleton in action: lissencephaly, a neuronal migration disorder.'
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
Since microtubule (MT) and actin-associated proteins play important
functions in regulating the dynamics of MT and actin cytoskeletons
during neuronal migration, genetic mutations or deletions of crucial
genes involved in cytoskeletal processes lead to lissencephaly in
human and neuronal migration defects in mouse.
explanation: >-
Supports cytoskeletal/microtubule dysfunction as the molecular basis
for the migration defect underlying lissencephaly.
- reference: PMID:23495356
reference_title: 'Cytoskeleton in action: lissencephaly, a neuronal migration disorder.'
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
During neuronal migration, MT organization and transport are
controlled by platelet-activating factor acetylhydrolase isoform 1b
regulatory subunit 1 (PAFAH1B1, formerly known as LIS1,
Lissencephaly-1), doublecortin (DCX), YWHAE, and tubulin.
explanation: >-
Names the key microtubule-regulating proteins (LIS1/PAFAH1B1, DCX,
tubulin) whose mutations cause classic lissencephaly.
downstream:
- target: Impaired Neuronal Migration
description: >-
Disruption of the LIS1/DCX/tubulin microtubule machinery impairs the
nucleokinesis and somal translocation that radially migrating cortical
neurons require, producing the migration arrest underlying lissencephaly.
- name: LIS1-NUDEL-Dynein Nucleokinesis Failure
conforms_to: "microtubule_dependent_neuronal_migration_failure#Microtubule-Based Neuronal Motility Failure"
description: >-
PAFAH1B1/LIS1 dosage loss disrupts a LIS1-NUDEL-cytoplasmic dynein heavy
chain complex that normally regulates dynein on microtubules during
neuronal migration. The resulting defect impairs centrosome-nucleus coupling
and nucleokinesis in migrating cortical neurons, producing the classical
type I lissencephaly/SBH migration-arrest branch. Mouse allelic series show
that lower Pafah1b1 activity causes progressively more severe neuronal
migration and brain-organization defects, matching the clinical severity
gradient from pachygyria/SBH toward more severe lissencephaly.
genes:
- preferred_term: PAFAH1B1
term:
id: hgnc:8574
label: PAFAH1B1
- preferred_term: NDEL1
term:
id: hgnc:17620
label: NDEL1
cell_types:
- preferred_term: migrating cortical neuron
term:
id: CL:0000540
label: neuron
biological_processes:
- preferred_term: nucleokinesis during radial migration
term:
id: GO:0021817
label: nucleokinesis involved in cell motility in cerebral cortex radial glia guided migration
modifier: ABNORMAL
- preferred_term: microtubule-based movement
term:
id: GO:0007018
label: microtubule-based movement
modifier: DYSREGULATED
evidence:
- reference: PMID:11163259
reference_title: "A LIS1/NUDEL/cytoplasmic dynein heavy chain complex in the developing and adult nervous system."
supports: SUPPORT
evidence_source: IN_VITRO
snippet: >-
we demonstrate that LIS1 directly interacts with the cytoplasmic dynein
heavy chain (CDHC) and NUDEL
explanation: >-
Demonstrates the core LIS1-NUDEL-dynein molecular complex underlying the
neuronal migration branch.
- reference: PMID:16481446
reference_title: "Regulation of cytoplasmic dynein ATPase by Lis1."
supports: SUPPORT
evidence_source: IN_VITRO
snippet: >-
recombinant Lis1 binds to native brain dynein and significantly increases
the microtubule-stimulated enzymatic activity of dynein in vitro.
explanation: >-
Shows that LIS1 directly modulates dynein enzymatic activity, connecting
PAFAH1B1 loss to microtubule motor dysfunction.
- reference: PMID:9697693
reference_title: "Graded reduction of Pafah1b1 (Lis1) activity results in neuronal migration defects and early embryonic lethality."
supports: SUPPORT
evidence_source: MODEL_ORGANISM
snippet: >-
Mice with one inactive allele display cortical, hippocampal and olfactory
bulb disorganization resulting from delayed neuronal migration by a
cell-autonomous neuronal pathway.
explanation: >-
Supports dosage-sensitive LIS1 neuronal migration failure in vivo.
downstream:
- target: Impaired Neuronal Migration
description: >-
Disruption of the LIS1-NUDEL-dynein motor pathway impairs nucleokinesis
and radial migration, converging on the lissencephaly cortical-lamination
defect.
- name: DCX Microtubule Stabilization Failure
conforms_to: "microtubule_dependent_neuronal_migration_failure#Microtubule Apparatus Perturbation"
description: >-
DCX encodes a neuronal microtubule-associated protein required for normal
migration of cortical neurons. Pathogenic DCX variants impair the
microtubule-stabilizing and tubulin-polymerizing function of doublecortin,
slowing or arresting migration. Hemizygous males usually develop
anterior-predominant classic lissencephaly, whereas heterozygous females
often develop subcortical band heterotopia through X-linked mosaicism.
genes:
- preferred_term: DCX
term:
id: hgnc:2714
label: DCX
cell_types:
- preferred_term: migrating cortical neuron
term:
id: CL:0000540
label: neuron
biological_processes:
- preferred_term: microtubule cytoskeleton organization
term:
id: GO:0000226
label: microtubule cytoskeleton organization
modifier: DYSREGULATED
- preferred_term: cytoplasmic microtubule organization
term:
id: GO:0031122
label: cytoplasmic microtubule organization
modifier: DECREASED
evidence:
- reference: PMID:9489700
reference_title: "Doublecortin, a brain-specific gene mutated in human X-linked lissencephaly and double cortex syndrome, encodes a putative signaling protein."
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
X-linked lissencephaly and "double cortex" are allelic human disorders
mapping to Xq22.3-Xq23 associated with arrest of migrating cerebral
cortical neurons.
explanation: >-
Establishes DCX-related lissencephaly and double-cortex/SBH as allelic
human neuronal-migration arrest disorders.
- reference: PMID:10399933
reference_title: "Doublecortin is a microtubule-associated protein and is expressed widely by migrating neurons."
supports: SUPPORT
evidence_source: IN_VITRO
snippet: >-
DCX coassembles with brain microtubules, and recombinant DCX stimulates
the polymerization of purified tubulin.
explanation: >-
Supports the microtubule-stabilization and tubulin-polymerization branch
of DCX disease biology.
- reference: PMID:10399933
reference_title: "Doublecortin is a microtubule-associated protein and is expressed widely by migrating neurons."
supports: SUPPORT
evidence_source: IN_VITRO
snippet: >-
DCX likely directs neuronal migration by regulating the organization and
stability of microtubules.
explanation: >-
Links DCX microtubule organization and stability to neuronal migration.
downstream:
- target: Impaired Neuronal Migration
description: >-
Loss of DCX microtubule stabilization disrupts migration of cortical
neurons, producing lissencephaly or subcortical band heterotopia depending
on sex, mosaicism, and variant context.
- name: LIS1 Progenitor Spindle Orientation Defect
conforms_to: "neural_progenitor_centrosome_spindle_dysfunction#Centrosome and Mitotic Spindle Perturbation"
description: >-
In addition to the postmitotic neuronal migration branch, PAFAH1B1/LIS1 loss
perturbs neuroepithelial and radial-glial progenitor mitotic spindle
orientation through LIS1/NDEL1/dynein-mediated cortical microtubule capture.
This progenitor branch affects symmetric division, progenitor expansion and
cortical neuron output, explaining why PAFAH1B1 disease can include cortical
thickness, simplified gyration and severity features not captured by a
migration-only model.
genes:
- preferred_term: PAFAH1B1
term:
id: hgnc:8574
label: PAFAH1B1
- preferred_term: NDEL1
term:
id: hgnc:17620
label: NDEL1
cell_types:
- preferred_term: neuroepithelial stem cell
term:
id: CL:0011020
label: neural progenitor cell
- preferred_term: radial glial progenitor
term:
id: CL:0000681
label: radial glial cell
biological_processes:
- preferred_term: mitotic spindle organization
term:
id: GO:0007052
label: mitotic spindle organization
modifier: DYSREGULATED
- preferred_term: cell division
term:
id: GO:0051301
label: cell division
modifier: DYSREGULATED
evidence:
- reference: PMID:18267077
reference_title: "Neuroepithelial stem cell proliferation requires LIS1 for precise spindle orientation and symmetric division."
supports: SUPPORT
evidence_source: MODEL_ORGANISM
snippet: >-
Lis1 is essential for precise control of mitotic spindle orientation in
both neuroepithelial stem cells and radial glial progenitor cells.
explanation: >-
Supports a LIS1 progenitor-spindle branch in neuroepithelial and radial
glial progenitors.
- reference: PMID:18267077
reference_title: "Neuroepithelial stem cell proliferation requires LIS1 for precise spindle orientation and symmetric division."
supports: SUPPORT
evidence_source: MODEL_ORGANISM
snippet: >-
control of symmetric division, essential for neuroepithelial stem cell
proliferation, is mediated through spindle orientation determined via
LIS1/NDEL1/dynein-mediated cortical microtubule capture.
explanation: >-
Links the progenitor division phenotype to the LIS1/NDEL1/dynein
microtubule-capture mechanism.
downstream:
- target: Impaired Neuronal Migration
description: >-
The progenitor-spindle branch changes cortical neuron output and cortical
organization, worsening the same abnormal cortical lamination endpoint as
the neuronal migration branch.
- name: Reelin Signaling Deficiency
description: >-
RELN encodes the large secreted glycoprotein reelin, which acts on
migrating cortical neurons by binding lipoprotein receptors (VLDLR and
ApoER2). Loss-of-function RELN mutations cause an autosomal recessive
lissencephaly with cerebellar hypoplasia, reflecting reelin's role in
directing cortical neuronal migration and laminar positioning.
cell_types:
- preferred_term: migrating cortical neuron
term:
id: CL:0000540
label: neuron
biological_processes:
- preferred_term: neuron migration
term:
id: GO:0001764
label: neuron migration
modifier: DECREASED
evidence:
- reference: PMID:10973257
reference_title: Autosomal recessive lissencephaly with cerebellar hypoplasia is associated with human RELN mutations.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
An autosomal recessive form of lissencephaly (LCH) associated with
severe abnormalities of the cerebellum, hippocampus and brainstem maps
to chromosome 7q22, and is associated with two independent mutations
in the human gene encoding reelin (RELN).
explanation: >-
Establishes RELN loss of function as a recessive cause of
lissencephaly with cerebellar hypoplasia.
- reference: PMID:10973257
reference_title: Autosomal recessive lissencephaly with cerebellar hypoplasia is associated with human RELN mutations.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
RELN encodes a large (388 kD) secreted protein that acts on migrating
cortical neurons by binding to the very low density lipoprotein
receptor (VLDLR), the apolipoprotein E receptor 2 (ApoER2; refs 9-11
), alpha3beta1 integrin and protocadherins.
explanation: >-
Describes the molecular mechanism by which reelin signaling guides
migrating cortical neurons, lost in RELN-related lissencephaly.
downstream:
- target: Impaired Neuronal Migration
description: >-
Loss of reelin signaling to migrating cortical neurons disrupts the
orderly inside-out cortical lamination, producing the migration defect
underlying RELN-related lissencephaly with cerebellar hypoplasia.
phenotypes:
- name: Lissencephaly
description: >-
A smooth cerebral surface with absent or reduced gyration (agyria or
pachygyria) due to arrest of neuronal migration and cortical
dyslamination.
phenotype_term:
preferred_term: Lissencephaly
term:
id: HP:0001339
label: Lissencephaly
evidence:
- reference: PMID:23495356
reference_title: 'Cytoskeleton in action: lissencephaly, a neuronal migration disorder.'
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
The brains of lissencephaly patients have less-convoluted gyri in the
cerebral cortex with impaired cortical lamination of neurons.
explanation: >-
Directly describes the defining lissencephaly imaging/pathology
phenotype of reduced gyration and impaired lamination.
- name: Pachygyria
description: >-
Broad, abnormally thick gyri with reduced sulcation, a milder pattern
within the lissencephaly spectrum, often posterior-predominant in
LIS1/PAFAH1B1 disease.
phenotype_term:
preferred_term: Pachygyria
term:
id: HP:0001302
label: Pachygyria
evidence:
- reference: PMID:29671837
reference_title: Analysis of 17 genes detects mutations in 81% of 811 patients with lissencephaly.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
The majority of unsolved patients had posterior pachygyria,
subcortical band heterotopia, or mild frontal pachygyria.
explanation: >-
Documents pachygyria (posterior and frontal) as a recognized pattern
within the lissencephaly spectrum cohort.
- name: Subcortical Band Heterotopia
description: >-
A band of arrested, heterotopic neurons in the white matter beneath the
cortex ("double cortex"), characteristically seen in females with
DCX-related disorders.
phenotype_term:
preferred_term: Subcortical band heterotopia
term:
id: HP:0032409
label: Subcortical band heterotopia
evidence:
- reference: PMID:20301364
reference_title: DCX-Related Disorders.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
DCX-related disorders include the following neuronal migration
disorders: classic thick lissencephaly (more severe anteriorly),
usually in males, and subcortical band heterotopia (SBH), primarily in
females.
explanation: >-
GeneReviews documents subcortical band heterotopia as a core
DCX-related lissencephaly-spectrum phenotype, predominantly in females.
- name: Seizures
description: >-
Epilepsy occurs in the great majority of individuals with classic
lissencephaly, frequently includes infantile spasms, and is often
drug-resistant.
phenotype_term:
preferred_term: Seizure
term:
id: HP:0001250
label: Seizure
frequency: VERY_FREQUENT
evidence:
- reference: PMID:20301752
reference_title: PAFAH1B1-Related Lissencephaly / Subcortical Band Heterotopia.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
Seizures occur in more than 90% of individuals with lissencephaly and
often include infantile spasms.
explanation: >-
GeneReviews documents seizures in >90% of individuals with
lissencephaly, supporting both the association and a VERY_FREQUENT
frequency band.
- name: Infantile Spasms
description: >-
An early-onset epileptic encephalopathy commonly seen in lissencephaly,
often refractory to anti-seizure medication.
phenotype_term:
preferred_term: Infantile spasms
term:
id: HP:0012469
label: Infantile spasms
evidence:
- reference: PMID:20301752
reference_title: PAFAH1B1-Related Lissencephaly / Subcortical Band Heterotopia.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
Seizures occur in more than 90% of individuals with lissencephaly and
often include infantile spasms.
explanation: >-
GeneReviews explicitly notes that lissencephaly-associated seizures
often include infantile spasms.
- name: Hypotonia
description: >-
Affected newborns typically have mild-to-moderate axial hypotonia and poor
head control, which may transition over time to spasticity.
phenotype_term:
preferred_term: Hypotonia
term:
id: HP:0001252
label: Hypotonia
evidence:
- reference: PMID:20301752
reference_title: PAFAH1B1-Related Lissencephaly / Subcortical Band Heterotopia.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
Affected newborns typically have mild-to-moderate hypotonia, feeding
difficulties, and poor head control.
explanation: >-
GeneReviews documents early hypotonia as a characteristic feature of
PAFAH1B1-related lissencephaly.
- name: Spasticity
description: >-
Mild distal spasticity emerging in the first years that can progress to
more severe spasticity, following early hypotonia.
phenotype_term:
preferred_term: Spasticity
term:
id: HP:0001257
label: Spasticity
clinical_course: PROGRESSIVE
evidence:
- reference: PMID:20301752
reference_title: PAFAH1B1-Related Lissencephaly / Subcortical Band Heterotopia.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
axial hypotonia, and mild distal spasticity that can transition over
time to more severe spasticity.
explanation: >-
GeneReviews documents distal spasticity that progresses over time in
PAFAH1B1-related lissencephaly.
- name: Intellectual Disability
description: >-
Developmental delay and intellectual disability are near-universal,
ranging from mild to severe; the best developmental level achieved in
classic lissencephaly is often only that of a 3-5 month-old infant.
phenotype_term:
preferred_term: Intellectual disability
term:
id: HP:0001249
label: Intellectual disability
evidence:
- reference: PMID:20301752
reference_title: PAFAH1B1-Related Lissencephaly / Subcortical Band Heterotopia.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
In individuals with PAFAH1B1-related lissencephaly/SBH, developmental
delay ranges from mild to severe.
explanation: >-
GeneReviews documents developmental delay/intellectual disability of
variable severity as a core feature.
- name: Feeding Difficulties
description: >-
Feeding issues and aspiration are common and may require gastrostomy tube
placement; dysphagia contributes to failure to thrive and aspiration
pneumonia.
phenotype_term:
preferred_term: Feeding difficulties
term:
id: HP:0011968
label: Feeding difficulties
evidence:
- reference: PMID:20301752
reference_title: PAFAH1B1-Related Lissencephaly / Subcortical Band Heterotopia.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
Other findings in PAFAH1B1-related lissencephaly/SBH include feeding
issues and aspiration (which may result in need for gastrostomy tube
placement), progressive microcephaly, and occasional developmental
regression.
explanation: >-
GeneReviews documents feeding issues and aspiration requiring
gastrostomy as common complications.
- name: Progressive Microcephaly
description: >-
Head growth deceleration leading to progressive (acquired/postnatal)
microcephaly is a recognized feature of PAFAH1B1-related lissencephaly.
phenotype_term:
preferred_term: Progressive microcephaly
term:
id: HP:0000252
label: Microcephaly
clinical_course: PROGRESSIVE
evidence:
- reference: PMID:20301752
reference_title: PAFAH1B1-Related Lissencephaly / Subcortical Band Heterotopia.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
feeding issues and aspiration (which may result in need for
gastrostomy tube placement), progressive microcephaly, and occasional
developmental regression.
explanation: >-
GeneReviews documents progressive microcephaly among the findings of
PAFAH1B1-related lissencephaly.
- name: Cerebellar Hypoplasia
description: >-
RELN-related autosomal recessive lissencephaly is distinguished by severe
cerebellar hypoplasia together with hippocampal and brainstem
abnormalities.
phenotype_term:
preferred_term: Cerebellar hypoplasia
term:
id: HP:0001321
label: Cerebellar hypoplasia
subtype: RELN-related
evidence:
- reference: PMID:10973257
reference_title: Autosomal recessive lissencephaly with cerebellar hypoplasia is associated with human RELN mutations.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
An autosomal recessive form of lissencephaly (LCH) associated with
severe abnormalities of the cerebellum, hippocampus and brainstem maps
to chromosome 7q22, and is associated with two independent mutations
in the human gene encoding reelin (RELN).
explanation: >-
Documents severe cerebellar (and hippocampal/brainstem) abnormalities
as the hallmark distinguishing RELN-related recessive lissencephaly.
- name: Visual Impairment
description: >-
Infants with classic (PAFAH1B1-related) lissencephaly typically show poor
visual tracking and reduced response to sounds during the first years of
life.
phenotype_term:
preferred_term: Poor visual tracking
term:
id: HP:0000505
label: Visual impairment
subtype: Classic/LIS1
evidence:
- reference: PMID:20301752
reference_title: PAFAH1B1-Related Lissencephaly / Subcortical Band Heterotopia.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
visual tracking and response to sounds
explanation: >-
PAFAH1B1 GeneReviews documents poor visual tracking among the early
neurologic findings of classic lissencephaly.
has_subtypes:
- name: Classic/LIS1
display_name: Classic lissencephaly (PAFAH1B1/LIS1-related)
subtype_term:
preferred_term: classic lissencephaly
term:
id: MONDO:0015146
label: classic lissencephaly
description: >-
The most common classic lissencephaly, caused by heterozygous PAFAH1B1
(LIS1) variants or 17p13.3 deletions, usually de novo. Imaging typically
shows posterior-predominant agyria/pachygyria. Seizures occur in >90% of
individuals and developmental delay ranges from mild to severe.
genes:
- preferred_term: PAFAH1B1
term:
id: hgnc:8574
label: PAFAH1B1
evidence:
- reference: PMID:29671837
reference_title: Analysis of 17 genes detects mutations in 81% of 811 patients with lissencephaly.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
LIS1 accounted for 40% of patients, followed by DCX (23%), TUBA1A
(5%), and DYNC1H1 (3%).
explanation: >-
In a cohort of 811 patients, LIS1/PAFAH1B1 was the single most common
cause of lissencephaly, defining the classic subtype.
- name: X-linked/DCX
display_name: X-linked lissencephaly / SBH (DCX-related)
description: >-
X-linked DCX-related disorder: males typically have classic thick
lissencephaly (more severe anteriorly) while heterozygous females present
with subcortical band heterotopia (double cortex). Phenotype severity
correlates with the degree of malformation on imaging.
genes:
- preferred_term: DCX
term:
id: hgnc:2714
label: DCX
inheritance:
- name: X-linked
inheritance_term:
preferred_term: X-linked inheritance
term:
id: HP:0001417
label: X-linked inheritance
evidence:
- reference: PMID:20301364
reference_title: DCX-Related Disorders.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: "DCX-related disorders are inherited in an X-linked manner."
explanation: >-
GeneReviews establishes X-linked inheritance for DCX-related
lissencephaly/SBH.
evidence:
- reference: PMID:20301364
reference_title: DCX-Related Disorders.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
DCX-related disorders include the following neuronal migration
disorders: classic thick lissencephaly (more severe anteriorly),
usually in males, and subcortical band heterotopia (SBH), primarily in
females.
explanation: >-
GeneReviews defines the X-linked DCX subtype with classic
lissencephaly in males and SBH in females.
- name: Tubulinopathy/TUBA1A
display_name: Tubulinopathy-associated lissencephaly (TUBA1A and related tubulins)
description: >-
Lissencephaly arising from mutations in tubulin genes (notably TUBA1A,
also TUBG1, TUBB2B, TUBB3), typically de novo autosomal dominant. The
malformation pattern often combines lissencephaly/pachygyria with
cerebellar, brainstem and basal ganglia abnormalities (corpus callosum
and internal capsule dysmorphism).
genes:
- preferred_term: TUBA1A
term:
id: hgnc:20766
label: TUBA1A
- preferred_term: TUBG1
term:
id: hgnc:12417
label: TUBG1
evidence:
- reference: PMID:29671837
reference_title: Analysis of 17 genes detects mutations in 81% of 811 patients with lissencephaly.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
LIS1 accounted for 40% of patients, followed by DCX (23%), TUBA1A
(5%), and DYNC1H1 (3%).
explanation: >-
TUBA1A is the most frequent tubulin-gene cause of lissencephaly in a
large cohort, defining the tubulinopathy subtype.
- name: ARX-related
display_name: ARX-related lissencephaly (XLAG spectrum)
subtype_term:
preferred_term: X-linked lissencephaly with abnormal genitalia
term:
id: MONDO:0010268
label: X-linked lissencephaly with abnormal genitalia
description: >-
X-linked lissencephaly associated with ARX variants, classically X-linked
lissencephaly with abnormal genitalia (XLAG) in males, a distinct
anterior-predominant form within the spectrum.
genes:
- preferred_term: ARX
term:
id: hgnc:18060
label: ARX
evidence:
- reference: PMID:29671837
reference_title: Analysis of 17 genes detects mutations in 81% of 811 patients with lissencephaly.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
Many were tested for deletion 17p13.3 and mutations of LIS1, DCX, and
ARX, but few other genes.
explanation: >-
ARX is one of the established lissencephaly-associated genes routinely
tested in the diagnostic workup.
- name: RELN-related
display_name: RELN-related lissencephaly with cerebellar hypoplasia
subtype_term:
preferred_term: lissencephaly with cerebellar hypoplasia
term:
id: MONDO:0019450
label: lissencephaly with cerebellar hypoplasia
description: >-
Autosomal recessive lissencephaly with cerebellar hypoplasia (LCH) caused
by biallelic RELN loss-of-function mutations, with severe cerebellar,
hippocampal and brainstem abnormalities reflecting deficient reelin
signaling.
genes:
- preferred_term: RELN
term:
id: hgnc:9957
label: RELN
evidence:
- reference: PMID:10973257
reference_title: Autosomal recessive lissencephaly with cerebellar hypoplasia is associated with human RELN mutations.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
An autosomal recessive form of lissencephaly (LCH) associated with
severe abnormalities of the cerebellum, hippocampus and brainstem maps
to chromosome 7q22, and is associated with two independent mutations
in the human gene encoding reelin (RELN).
explanation: >-
Defines the RELN-related recessive subtype with cerebellar hypoplasia.
- name: Cobblestone
display_name: Cobblestone lissencephaly (dystroglycanopathy)
subtype_term:
preferred_term: cobblestone lissencephaly
term:
id: MONDO:0018869
label: cobblestone lissencephaly
description: >-
A distinct "type II"/cobblestone form in which neurons overmigrate through
a disrupted pial basement membrane, associated with glycosylation-pathway
genes such as POMGNT1, POMT1 and POMT2 (alpha-dystroglycanopathies),
typically with eye and muscle involvement. Neuropathology differs from the
classic (migration-arrest) forms.
genes:
- preferred_term: POMGNT1
term:
id: hgnc:19139
label: POMGNT1
- preferred_term: POMT1
term:
id: hgnc:9202
label: POMT1
- preferred_term: POMT2
term:
id: hgnc:19743
label: POMT2
genetic:
- name: PAFAH1B1
association: Loss of function
subtype: Classic/LIS1
gene_term:
preferred_term: PAFAH1B1
term:
id: hgnc:8574
label: PAFAH1B1
evidence:
- reference: PMID:29671837
reference_title: Analysis of 17 genes detects mutations in 81% of 811 patients with lissencephaly.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
LIS1 accounted for 40% of patients, followed by DCX (23%), TUBA1A
(5%), and DYNC1H1 (3%).
explanation: >-
LIS1/PAFAH1B1 is the most common genetic cause of lissencephaly in an
811-patient cohort.
- reference: PMID:20301752
reference_title: PAFAH1B1-Related Lissencephaly / Subcortical Band Heterotopia.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
The diagnosis of PAFAH1B1-related lissencephaly/SBH is established in a
proband with a heterozygous pathogenic variant in PAFAH1B1 identified
by molecular genetic testing.
explanation: >-
GeneReviews confirms heterozygous PAFAH1B1 pathogenic variants as
causal for classic lissencephaly/SBH.
- name: DCX
association: Loss of function
subtype: X-linked/DCX
gene_term:
preferred_term: DCX
term:
id: hgnc:2714
label: DCX
evidence:
- reference: PMID:20301364
reference_title: DCX-Related Disorders.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
The diagnosis of a DCX-related disorder is established in a proband
with a DCX pathogenic variant identified by molecular genetic testing.
explanation: >-
GeneReviews confirms DCX pathogenic variants as causal for X-linked
lissencephaly/SBH.
- reference: PMID:29671837
reference_title: Analysis of 17 genes detects mutations in 81% of 811 patients with lissencephaly.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
LIS1 accounted for 40% of patients, followed by DCX (23%), TUBA1A
(5%), and DYNC1H1 (3%).
explanation: >-
DCX is the second most common lissencephaly gene in a large cohort.
- name: TUBA1A
association: Pathogenic variant
subtype: Tubulinopathy/TUBA1A
gene_term:
preferred_term: TUBA1A
term:
id: hgnc:20766
label: TUBA1A
evidence:
- reference: PMID:29671837
reference_title: Analysis of 17 genes detects mutations in 81% of 811 patients with lissencephaly.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
LIS1 accounted for 40% of patients, followed by DCX (23%), TUBA1A
(5%), and DYNC1H1 (3%).
explanation: >-
TUBA1A is an established lissencephaly gene and the most common
tubulin-gene cause in this cohort.
- name: DYNC1H1
association: Pathogenic variant
gene_term:
preferred_term: DYNC1H1
term:
id: hgnc:2961
label: DYNC1H1
evidence:
- reference: PMID:29671837
reference_title: Analysis of 17 genes detects mutations in 81% of 811 patients with lissencephaly.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
LIS1 accounted for 40% of patients, followed by DCX (23%), TUBA1A
(5%), and DYNC1H1 (3%).
explanation: >-
DYNC1H1, encoding the dynein heavy chain, is a recognized
lissencephaly gene consistent with the dynein/migration mechanism.
- name: RELN
association: Loss of function
subtype: RELN-related
gene_term:
preferred_term: RELN
term:
id: hgnc:9957
label: RELN
evidence:
- reference: PMID:10973257
reference_title: Autosomal recessive lissencephaly with cerebellar hypoplasia is associated with human RELN mutations.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
The mutations disrupt splicing of RELN cDNA, resulting in low or
undetectable amounts of reelin protein.
explanation: >-
Documents RELN loss-of-function (splicing-disrupting) variants causing
recessive lissencephaly with cerebellar hypoplasia.
- name: ARX
association: Pathogenic variant
subtype: ARX-related
gene_term:
preferred_term: ARX
term:
id: hgnc:18060
label: ARX
evidence:
- reference: PMID:29671837
reference_title: Analysis of 17 genes detects mutations in 81% of 811 patients with lissencephaly.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
Many were tested for deletion 17p13.3 and mutations of LIS1, DCX, and
ARX, but few other genes.
explanation: >-
ARX is an established X-linked lissencephaly gene included in standard
diagnostic testing.
treatments:
- name: Anti-Seizure Medication
description: >-
Standard anti-seizure medication selected by seizure type; in
PAFAH1B1-related lissencephaly, polytherapy with valproic acid and
lamotrigine appears most effective for drug-resistant seizures. Seizures
are often refractory.
treatment_term:
preferred_term: pharmacotherapy
term:
id: NCIT:C15986
label: Pharmacotherapy
therapeutic_agent:
- preferred_term: valproic acid
term:
id: CHEBI:39867
label: valproic acid
- preferred_term: lamotrigine
term:
id: CHEBI:6367
label: lamotrigine
evidence:
- reference: PMID:20301752
reference_title: PAFAH1B1-Related Lissencephaly / Subcortical Band Heterotopia.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
polytherapy with valproic acid and lamotrigine appears most effective
in reducing drug-resistant seizures
explanation: >-
GeneReviews recommends valproic acid plus lamotrigine polytherapy for
drug-resistant seizures in PAFAH1B1-related lissencephaly.
- name: Gastrostomy and Feeding Support
description: >-
Placement of a gastrostomy tube for individuals with failure to thrive,
dysphagia, and/or recurrent aspiration pneumonia, with feeding strategies
for newborns with poor suck and swallow.
treatment_term:
preferred_term: gastrostomy
term:
id: MAXO:0001346
label: gastrostomy
evidence:
- reference: PMID:20301752
reference_title: PAFAH1B1-Related Lissencephaly / Subcortical Band Heterotopia.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
placement of a gastrostomy tube for those with failure to thrive,
dysphagia, and/or recurrent aspiration pneumonia
explanation: >-
GeneReviews recommends gastrostomy for feeding failure and aspiration
risk in lissencephaly.
- name: Physical Therapy
description: >-
Physical therapy to promote mobility and prevent contractures; in patient
cohorts physiotherapy is reported among the most effective supportive
therapies.
treatment_term:
preferred_term: Physical Therapy
term:
id: NCIT:C15302
label: Physical Therapy
evidence:
- reference: PMID:20301364
reference_title: DCX-Related Disorders.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
physical therapy to promote mobility and prevent contractures
explanation: >-
GeneReviews recommends physical therapy to support mobility and
prevent contractures in DCX-related disorders.
- name: Occupational Therapy
description: >-
Occupational therapy to improve fine motor skills and oral motor control,
as part of multidisciplinary supportive management of lissencephaly.
treatment_term:
preferred_term: occupational therapy
term:
id: MAXO:0001351
label: occupational therapy
evidence:
- reference: PMID:20301364
reference_title: DCX-Related Disorders.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
occupational therapy to improve fine motor skills
explanation: >-
GeneReviews recommends occupational therapy to improve fine and oral
motor skills in DCX-related lissencephaly.
- name: Speech Therapy
description: >-
Speech therapy to support communication and oral-motor function as part of
multidisciplinary supportive management.
treatment_term:
preferred_term: speech therapy
term:
id: MAXO:0000930
label: speech therapy
evidence:
- reference: PMID:20301364
reference_title: DCX-Related Disorders.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
participation in speech therapy
explanation: >-
GeneReviews includes speech therapy in the supportive management of
DCX-related lissencephaly.
- name: Genetic Counseling
description: >-
Genetic counseling and reproductive options (prenatal and preimplantation
genetic testing) once a familial pathogenic variant is identified;
important given the high de novo rate and variable inheritance across the
spectrum.
treatment_term:
preferred_term: Genetic Counseling
term:
id: NCIT:C15240
label: Genetic Counseling
evidence:
- reference: PMID:20301364
reference_title: DCX-Related Disorders.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
Once the DCX pathogenic variant has been identified in an affected
family member, prenatal and preimplantation genetic testing are
possible.
explanation: >-
GeneReviews supports genetic counseling with prenatal/preimplantation
testing once the familial variant is known.
discussions:
- discussion_id: gap_pafah1b1_dcx_gradient_and_cellular_emphasis
prompt: >-
What explains the opposite anterior-posterior severity gradients and
cellular emphasis between PAFAH1B1/LIS1 and DCX disease when both converge
on microtubule-dependent neuronal migration failure?
kind: KNOWLEDGE_GAP
status: OPEN
attaches_to:
- pathophysiology#LIS1-NUDEL-Dynein Nucleokinesis Failure
- pathophysiology#DCX Microtubule Stabilization Failure
- pathophysiology#LIS1 Progenitor Spindle Orientation Defect
rationale: >-
PAFAH1B1/LIS1 and DCX share a migration-failure endpoint, but the human
radiographic gradients and cellular branches differ: PAFAH1B1 has a
LIS1/NUDEL/dynein motor branch plus a progenitor-spindle component, whereas
DCX disease is typically anterior-predominant in males and SBH in
heterozygous females. The unresolved issue is whether regional expression,
different microtubule-motor versus lattice functions, X-inactivation
mosaicism, or human-specific progenitor context best explains these
genotype-specific patterns.
evidence:
- reference: PMID:11163259
reference_title: "A LIS1/NUDEL/cytoplasmic dynein heavy chain complex in the developing and adult nervous system."
supports: SUPPORT
evidence_source: IN_VITRO
snippet: >-
These results suggest that LIS1 and NUDEL regulate CDHC activity during
neuronal migration and axonal retrograde transport in a Cdk5/p35-dependent
fashion.
explanation: >-
Supports the LIS1/NUDEL/dynein branch as a distinct molecular mechanism
within the shared migration-failure endpoint.
- reference: PMID:18267077
reference_title: "Neuroepithelial stem cell proliferation requires LIS1 for precise spindle orientation and symmetric division."
supports: SUPPORT
evidence_source: MODEL_ORGANISM
snippet: >-
Lis1 is essential for precise control of mitotic spindle orientation in
both neuroepithelial stem cells and radial glial progenitor cells.
explanation: >-
Supports a PAFAH1B1/LIS1 progenitor branch not captured by a purely
postmitotic migration model.
- reference: PMID:20301364
reference_title: DCX-Related Disorders.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
classic thick lissencephaly (more severe anteriorly), usually in males,
and subcortical band heterotopia (SBH), primarily in females.
explanation: >-
Establishes the DCX anterior-predominant and sex-biased SBH pattern.
proposed_experiments:
- experiment_id: exp_lis1_dcx_isogenic_organoid_gradient_comparison
name: PAFAH1B1/DCX isogenic cortical-organoid gradient comparison
description: >-
Generate matched human iPSC-derived dorsal forebrain organoids with
PAFAH1B1 haploinsufficiency, DCX loss, and isogenic correction or knock-in
rescue. Compare regional patterning markers, radial-glial spindle
orientation, nucleokinesis, migration speed, microtubule lattice stability,
and mosaic DCX expression effects to distinguish regional-expression,
progenitor-spindle, and X-inactivation models.
experiment_type:
preferred_term: isogenic cerebral organoid migration and progenitor assay
model_systems:
- name: Human iPSC-derived dorsal forebrain organoid LIS/SBH model
description: >-
Isogenic human cortical organoids carrying PAFAH1B1 haploinsufficiency
or DCX loss/knock-in variants, with corrected and non-disease donor
controls.
experimental_model_type: ORGANOID
namo_type: namo:Organoid
organism:
preferred_term: human
term:
id: NCBITaxon:9606
label: Homo sapiens
tissue_term:
preferred_term: cerebral cortex
term:
id: UBERON:0000956
label: cerebral cortex
cell_types:
- preferred_term: radial glial cell
term:
id: CL:0000681
label: radial glial cell
- preferred_term: neuron
term:
id: CL:0000540
label: neuron
culture_system: Three-dimensional cerebral organoid with live-imaging and single-cell readouts
perturbations:
- name: PAFAH1B1 haploinsufficiency and DCX loss or mosaic knock-in
description: >-
CRISPR or patient-variant knock-in perturbations with isogenic repair,
including mixed DCX-positive and DCX-negative neuronal populations to
model female SBH mosaicism.
target: pathophysiology#DCX Microtubule Stabilization Failure
readouts:
- name: Regional gradient and migration metrics
target: pathophysiology#Impaired Neuronal Migration
description: >-
Quantify anterior/posterior patterning markers, radial-glial cleavage
orientation, centrosome-nucleus coupling, nuclear translocation speed,
tubulin polymerization/stability markers, and ectopic neuronal bands.
controls:
- name: Isogenic corrected controls
description: >-
Corrected PAFAH1B1 or DCX lines and non-disease donor organoids cultured
in parallel.
decision_criterion: >-
A disease-specific gradient mechanism is supported if PAFAH1B1 and DCX
perturbations diverge in regional patterning, progenitor-spindle, or
mosaic migration readouts despite shared downstream dyslamination.
would_support:
- pathophysiology#LIS1-NUDEL-Dynein Nucleokinesis Failure
- pathophysiology#DCX Microtubule Stabilization Failure
- pathophysiology#LIS1 Progenitor Spindle Orientation Defect
- discussion_id: gap_dcx_knockout_mouse_neocortex_model_mismatch
prompt: >-
Does the germline Dcx-knockout mouse — the founding animal model of DCX
disease — faithfully recapitulate the defining human DCX neocortical
malformation (X-linked lissencephaly in hemizygous males, subcortical band
heterotopia in heterozygous females), given that germline Dcx-null mice have
a near-normal neocortex, that only acute in utero RNAi knockdown reproduces a
radial-migration/heterotopia phenotype, and that even this RNAi phenotype
forms in rat but not in mouse — so that the severity and very existence of the
human neocortical lesion is systematically underdetermined by the standard
mouse knockout and its faithful modeling may require an acute-knockdown, a
redundancy-free (Dcx/Dclk compound), a rat, or a human-specific progenitor
context?
kind: HUMAN_MODEL_MISMATCH
status: OPEN
attaches_to:
- pathophysiology#DCX Microtubule Stabilization Failure
- pathophysiology#Impaired Neuronal Migration
rationale: >-
DCX is one of the most striking human/model discordances in the cortical
malformation literature, and it bears directly on how strongly the mouse can
validate the DCX branch of this entry. In humans, X-linked DCX mutations
cause classic thick lissencephaly in males and subcortical band heterotopia
in females — a severe, defining neocortical migration defect. Yet the
germline Dcx-knockout mouse has neocortical lamination largely
indistinguishable from wild type, with the migration/lamination phenotype
restricted to the hippocampus; the neocortical malformation only appears when
Dcx is acutely silenced by in utero RNAi rather than deleted in the germline.
Two overlapping explanations are documented: (1) developmental compensation /
genetic redundancy, whereby the paralog doublecortin-like kinase (Dclk)
substitutes for Dcx in the germline knockout but not under acute knockdown,
so that only Dcx/Dclk compound loss reproduces the migration defect; and (2)
a genuine species difference, since the same in utero RNAi against Dcx induces
band heterotopia in rat but fails to induce heterotopia in mouse. This is a
concrete instance of two knowledge gaps flagged by the Romero, Bahi-Buisson &
Francis 2018 cortical-malformation review that seeds this epic: that mouse
models often fail to reproduce human MCD features, and that acute in utero
knockdown can be more severe than germline knockout because of off-target
effects, developmental compensation, or redundancy revealed only by double
knockouts. Mechanistically it leaves open whether the human neocortical
lesion reflects reduced Dcx/Dclk-family redundancy in human migrating
neurons, a rat-like rather than mouse-like species requirement for Dcx in
neocortical radial migration, or a human-specific progenitor/outer-radial-glia
context — meaning the mouse germline knockout, taken alone, validates the DCX
microtubule-stabilization mechanism only weakly for the human neocortical
phenotype.
proposed_experiments:
- experiment_id: exp_dcx_dclk_compound_perturbation_rat_vs_mouse
name: Dcx germline-KO versus acute-knockdown and Dcx/Dclk compound loss, compared across rat and mouse
description: >-
Systematically dissociate the redundancy and species-difference hypotheses
by comparing germline Dcx knockout, acute in utero RNAi knockdown, and
Dcx/Dclk compound loss for their ability to produce neocortical band
heterotopia and laminar displacement, run in parallel in rat and mouse
embryos with rescue-by-Dcx-overexpression specificity controls. This tests
whether faithful modeling of the human neocortical phenotype requires
removing paralog compensation, using acute rather than germline
perturbation, and/or a rat rather than mouse substrate.
experiment_type:
preferred_term: in vivo rodent neuronal-migration perturbation study
model_systems:
- name: Rat and mouse embryonic neocortex (in utero electroporation)
description: >-
Developing rat and mouse cortex perturbed by in utero electroporation of
RNAi or gene-edited alleles, the paired system that first revealed the
rat-versus-mouse discrepancy in Dcx-knockdown heterotopia formation.
experimental_model_type: OTHER
- experiment_id: exp_dcx_human_ipsc_mosaic_migration_assay
name: Human iPSC-derived cortical model of DCX loss and female SBH mosaicism
description: >-
Generate isogenic DCX-null and DCX-variant human iPSC-derived cortical
organoids/assembloids, including mixed DCX-positive and DCX-negative
neuronal populations to model heterozygous-female mosaicism, and quantify
radial migration, laminar positioning, and heterotopic-band formation to
test whether a human progenitor/neuronal context reproduces the severe
neocortical phenotype that the mouse germline knockout does not.
experiment_type:
preferred_term: iPSC cortical organoid migration assay
model_systems:
- name: Human iPSC-derived cortical organoid/assembloid DCX model
description: >-
Isogenic human cortical organoids or assembloids carrying DCX loss or
patient variants with mosaic DCX expression, preserving human-specific
cortical progenitor biology absent from the mouse.
experimental_model_type: ORGANOID
evidence:
- reference: PMID:12196578
reference_title: "Doublecortin is required in mice for lamination of the hippocampus but not the neocortex."
supports: SUPPORT
evidence_source: MODEL_ORGANISM
snippet: >-
Dcx mutant mice show neocortical lamination that is largely
indistinguishable from wild type and show normal patterns of neocortical
neurogenesis and neuronal migration.
explanation: >-
The founding germline Dcx-knockout mouse report establishes the core
mismatch: the mouse neocortex is essentially normal despite DCX loss,
whereas the human neocortical phenotype (lissencephaly/SBH) is severe.
- reference: PMID:14625554
reference_title: "RNAi reveals doublecortin is required for radial migration in rat neocortex."
supports: SUPPORT
evidence_source: MODEL_ORGANISM
snippet: >-
Paradoxically, genetic deletion of Dcx in mice does not cause neocortical
malformation.
explanation: >-
Documents the acute-knockdown-versus-germline-knockout discrepancy: acute
in utero RNAi of DCX reproduces the migration defect that germline deletion
does not, one of the Romero review's flagged model caveats.
- reference: PMID:16292002
reference_title: "Heterotopia formation in rat but not mouse neocortex after RNA interference knockdown of DCX."
supports: SUPPORT
evidence_source: MODEL_ORGANISM
snippet: >-
In utero RNAi in the rat consistently leads to both the formation of SBH
and laminar displacement of transfected cells in normotopic cortex, whereas
the same treatment in mouse fails to induce SBH but does create laminar
displacement.
explanation: >-
Demonstrates a genuine rat-versus-mouse species difference in the Dcx-loss
neocortical phenotype, so even acute knockdown does not model the severe
human heterotopia in mouse.
- reference: PMID:16387639
reference_title: "Doublecortin-like kinase functions with doublecortin to mediate fiber tract decussation and neuronal migration."
supports: SUPPORT
evidence_source: MODEL_ORGANISM
snippet: >-
Humans with mutations show profound alterations in cortical lamination,
whereas in mouse, RNAi-mediated knockdown but not germline knockout shows
abnormal positioning of cortical neurons.
explanation: >-
Identifies partially redundant Dclk compensation as a mechanistic
explanation for why the germline Dcx-knockout mouse under-reproduces the
human phenotype, supporting the redundancy arm of the mismatch.
Lissencephaly spectrum disorders are malformations of cortical development (MCDs) characterized by abnormal cortical folding (reduced gyrification) due primarily to impaired neuronal migration and cortical lamination during embryonic development. (uctepe2024biallelictruncatingvariants pages 1-2, alsafh2024multiplexconsanguineousfamily pages 1-2)
A concise definition from a 2024 European Journal of Human Genetics report states: “Lissencephaly (LIS) is a malformation of cortical development due to deficient neuronal migration and abnormal formation of cerebral convolutions or gyri.” (uctepe2024biallelictruncatingvariants pages 1-2)
A core concept is that “lissencephaly” is not a single pattern but a spectrum that includes: - Agyria (near absence of gyri) - Pachygyria (broad, reduced number of gyri) - Subcortical band heterotopia (SBH) (a.k.a. double cortex) (uctepe2024biallelictruncatingvariants pages 1-2, tsai2024novellissencephalyassociatedndel1 pages 1-2)
A 2024 paper explicitly defines this: “LIS spectrum disorder includes agyria, pachygyria and subcortical band heterotopia.” (uctepe2024biallelictruncatingvariants pages 1-2)
From the tools used here, the disease has: - MONDO: MONDO:0018838 (OpenTargets Search: lissencephaly)
Other identifiers (OMIM disease numbers, Orphanet IDs, ICD-10/ICD-11, MeSH IDs) were not directly retrieved in the available evidence in this run and therefore are not reported here.
The evidence in this report comes from: - Aggregated disease-level resources/knowledge graphs (Open Targets). (OpenTargets Search: lissencephaly) - Human clinical genomics cohort studies and gene discovery/expansion papers (exome sequencing, GeneMatcher collaborations). (kooshavar2024diagnosticutilityof pages 1-3, uctepe2024biallelictruncatingvariants pages 1-2) - Mechanistic human genetics with model-based functional validation (mouse in utero electroporation; scRNA-seq; spatial transcriptomics). (tsai2024novellissencephalyassociatedndel1 pages 1-2)
Lissencephaly spectrum disorders are genetically heterogeneous, involving multiple pathways critical to neuronal migration, microtubule dynamics, dynein regulation, and cortical organization. Multiple papers emphasize microtubule/dynein/migration biology as central etiologic themes. (alsafh2024multiplexconsanguineousfamily pages 1-2, tsai2024novellissencephalyassociatedndel1 pages 1-2, pavone2023casereportstructural pages 1-2)
A 2024 NDEL1 paper highlights core upstream processes: “cell proliferation and migration, which rely on the motor protein dynein and its regulators NDE1 and NDEL1.” (tsai2024novellissencephalyassociatedndel1 pages 1-2)
Open Targets provides disease–target associations for lissencephaly and for MONDO:0018838 lissencephaly spectrum disorders, including (not exhaustive): DCX, PAFAH1B1 (LIS1), TUBA1A, ARX, RELN, CEP85L, LAMB1, MACF1, KATNB1, TMTC3, DYNC1H1, NDE1. (OpenTargets Search: lissencephaly)
Recent (2023–2024) primary literature expands the gene spectrum and clarifies inheritance modes:
Autosomal recessive (AR) examples / emerging genes - CASP2: 2024 GeneMatcher-based series of 7 patients from 5 families with biallelic truncating/compound heterozygous variants, described as “compatible with an autosomal recessive pattern.” (uctepe2024biallelictruncatingvariants pages 1-2) - CLASP1: 2024 report of three affected siblings with a homozygous CLASP1 variant from a consanguineous family; the paper notes that segregation suggests “a possible autosomal recessive inheritance.” (alsafh2024multiplexconsanguineousfamily pages 1-2)
Autosomal dominant (AD), often de novo examples (notably tubulinopathies) - TUBA1A: a 2024 case report/literature review states that for TUBA1A “most cases show de novo autosomal dominant inheritance,” consistent with broader tubulinopathy patterns. (ren2024lissencephalycausedby pages 1-2)
Somatic mosaicism - NDEL1 p.Arg105Pro: 2024 Acta Neuropathologica paper identified “the same de novo somatic mosaic NDEL1 variant” in two unrelated patients with pachygyria ± SBH. (tsai2024novellissencephalyassociatedndel1 pages 1-2)
X-linked - DCX is a major X-linked lissencephaly-spectrum gene in Open Targets. (OpenTargets Search: lissencephaly)
While environmental insults can contribute to cortical malformations, quantitative environmental risk/protective factor evidence specific to “lissencephaly spectrum disorders” was not retrieved in the evidence set used here. The available evidence emphasizes genetic causation in most described cases and cohorts. (kooshavar2024diagnosticutilityof pages 1-3, uctepe2024biallelictruncatingvariants pages 1-2)
Commonly reported features include: - Global developmental delay / intellectual disability (ID) (uctepe2024biallelictruncatingvariants pages 1-2) - Hypotonia (uctepe2024biallelictruncatingvariants pages 1-2) - Seizures / epilepsy, often early-onset and refractory (alsafh2024multiplexconsanguineousfamily pages 1-2, uctepe2024biallelictruncatingvariants pages 1-2) - Neurobehavioral phenotypes in subsets (ADHD, autistic traits, poor social skills) in CASP2-related cases (uctepe2024biallelictruncatingvariants pages 1-2)
Abstract quote (CASP2 series): “Other findings included developmental delay, attention deficit hyperactivity disorder, hypotonia, seizure, poor social skills, and autistic traits.” (uctepe2024biallelictruncatingvariants pages 1-2)
Lissencephaly-spectrum disorders typically present congenitally (structural brain malformation present at birth), with clinical manifestations in infancy (developmental delay and seizures often beginning early). In a long-term lissencephaly cohort, the median age at suspected diagnosis was reported as 5 months for LIS1/PAFAH1B1 and 9 months for DCX. (proepper2026genespecificlongtermcourse pages 6-11)
A long-term cohort study (published 2026) provides quantitative complication frequencies and supportive-care utilization; although slightly outside the requested 2023–2024 priority, these data are currently among the most detailed quantitative real-world outcomes located in the retrieved evidence: - Recurrent respiratory infections: 14/38 (37%) in LIS1/PAFAH1B1; 1/4 (25%) in DCX (proepper2026genespecificlongtermcourse pages 6-11) - Dysphagia/vomiting: 23/37 (62%) in LIS1/PAFAH1B1; 2/4 (50%) in DCX (proepper2026genespecificlongtermcourse pages 6-11) - Tube feeding required: 15/38 (40%) in LIS1/PAFAH1B1; 1/5 (20%) in DCX (proepper2026genespecificlongtermcourse pages 6-11) - Supportive therapies: median 8 therapies per patient (range 1–17) (proepper2026genespecificlongtermcourse pages 6-11)
Based on the phenotypes explicitly present in the evidence: - Lissencephaly (HP:0001339 appears as a disease entity in the Open Targets output) (OpenTargets Search: lissencephaly) - Microcephaly (mentioned as common and as a prenatal abnormality in cohorts) (hu2026prenataldiagnosisof pages 1-2, proepper2026genespecificlongtermcourse pages 6-11) - Seizures / epilepsy (alsafh2024multiplexconsanguineousfamily pages 1-2, uctepe2024biallelictruncatingvariants pages 1-2) - Hypotonia (uctepe2024biallelictruncatingvariants pages 1-2) - Developmental delay / intellectual disability (uctepe2024biallelictruncatingvariants pages 1-2) - Subcortical band heterotopia / double cortex (tsai2024novellissencephalyassociatedndel1 pages 1-2, uctepe2024biallelictruncatingvariants pages 1-2)
Frequency-by-HPO mapping beyond these qualitative statements was not available in the retrieved sources.
High-confidence, widely established genes: PAFAH1B1 (LIS1), DCX, ARX, RELN, TUBA1A, DYNC1H1, NDE1. (OpenTargets Search: lissencephaly, tsai2024novellissencephalyassociatedndel1 pages 1-2)
Recently expanded/implicated genes (2023–2024 evidence): - NDEL1 (somatic mosaic) (tsai2024novellissencephalyassociatedndel1 pages 1-2) - CASP2 (biallelic truncating variants; PIDDosome component) (uctepe2024biallelictruncatingvariants pages 1-2) - CLASP1 (candidate AR lissencephaly) (alsafh2024multiplexconsanguineousfamily pages 1-2)
Examples from recent evidence: - Truncating / splice-disrupting loss-of-function (AR): CASP2 truncating and splice-site variants, including frameshift and nonsense; RNA studies showed cryptic splicing generating premature stop codons. (uctepe2024biallelictruncatingvariants pages 1-2) - Missense variants with dominant effects (often de novo): NDEL1 p.Arg105Pro (somatic mosaic missense) (tsai2024novellissencephalyassociatedndel1 pages 1-2); TUBA1A p.Arg402Cys in a de novo case report (ren2024lissencephalycausedby pages 1-2)
Specific validated modifier genes or disease-specific epigenetic mechanisms were not retrieved in the evidence set.
General MCD resources emphasize chromosomal abnormalities as part of the etiologic spectrum, and Kooshavar et al. required prior chromosomal microarray (CMA) with exclusion of pathogenic CNVs. However, lissencephaly-specific CNV frequencies were not provided in the extracted evidence snippets. (kooshavar2024diagnosticutilityof pages 1-3)
No disease-specific environmental or lifestyle contributors were identified in the retrieved evidence set; the evidence emphasizes genetic causation and genomics-guided diagnosis. (kooshavar2024diagnosticutilityof pages 1-3, uctepe2024biallelictruncatingvariants pages 1-2)
A broadly supported mechanism is: 1) Pathogenic variants disrupt proteins governing neuronal migration/cytoskeletal dynamics (microtubules, dynein regulators, microtubule-associated proteins). (alsafh2024multiplexconsanguineousfamily pages 1-2, pavone2023casereportstructural pages 1-2) 2) This impairs nucleokinesis and/or radial migration and cortical layer formation. (tsai2024novellissencephalyassociatedndel1 pages 1-2) 3) The resulting cortical malformation manifests as agyria/pachygyria/SBH and commonly leads to epilepsy and neurodevelopmental disability. (uctepe2024biallelictruncatingvariants pages 1-2)
The 2024 Acta Neuropathologica study provides unusually direct mechanistic linkage from variant → molecular interaction → cellular process → phenotype: - “p.R105P expression alone strongly disrupted neuronal migration … and impaired nucleus–centrosome coupling, suggesting a failure in nucleokinesis.” (tsai2024novellissencephalyassociatedndel1 pages 1-2) - “Mechanistically, p.R105P disrupted NDEL1 binding to the dynein regulator LIS1.” (tsai2024novellissencephalyassociatedndel1 pages 1-2)
This paper also incorporates modern profiling approaches: “single-cell RNA sequencing and spatial transcriptomic analysis,” which showed complementary expression patterns (NDE1 in neural progenitors; NDEL1 in post-mitotic neurons). (tsai2024novellissencephalyassociatedndel1 pages 1-2)
The 2024 CASP2 study ties an apoptosis/inflammasome-like signaling complex to cortical development: “Recently, biallelic pathogenic variants in CRADD and PIDD1 have associated with LIS impacting the previously established role of the PIDDosome in activating caspase-2. In this report, we describe biallelic truncating variants in CASP2.” (uctepe2024biallelictruncatingvariants pages 1-2)
A 2023 review of TUBA1A tubulinopathies describes tubulinopathies as a heterogeneous group of tubulin-gene disorders with severe cortical and subcortical malformations, emphasizing microtubules as fundamental to neuronal migration, axonal transport, and connectivity. (pavone2023casereportstructural pages 1-2)
GO biological process (examples): neuronal migration; nucleokinesis; microtubule-based process; cortical layer formation (supported conceptually by dynein/migration mechanism and explicitly by the NDEL1 paper’s focus on neuronal migration and nucleokinesis). (tsai2024novellissencephalyassociatedndel1 pages 1-2)
Cell Ontology (CL) suggestions (examples): - Radial glial cells / neural progenitors (the NDEL1 paper explicitly discusses neural progenitors and radial glial cells in the ventricular zone) (tsai2024novellissencephalyassociatedndel1 pages 1-2) - Post-mitotic neurons (explicitly referenced in expression analysis) (tsai2024novellissencephalyassociatedndel1 pages 1-2)
UBERON suggestions: cerebral cortex; ventricular zone; subventricular zone; cortical plate (explicitly referenced anatomical compartments in the NDEL1 study). (tsai2024novellissencephalyassociatedndel1 pages 1-2)
Primary system: central nervous system, particularly the cerebral cortex (six-layered neocortex) and its gyral/sulcal architecture. (tsai2024novellissencephalyassociatedndel1 pages 1-2, uctepe2024biallelictruncatingvariants pages 1-2)
Key developmental compartments and cell types include ventricular zone progenitors (radial glial cells) and migrating post-mitotic neurons. (tsai2024novellissencephalyassociatedndel1 pages 1-2)
Structural malformation is congenital; clinical recognition often occurs in infancy. In one cohort, median suspected diagnosis age was 5–9 months depending on gene subgroup (LIS1 vs DCX). (proepper2026genespecificlongtermcourse pages 6-11)
Neurodevelopmental impairment and epilepsy frequently persist long-term; supportive therapies are heavily used by families. (proepper2026genespecificlongtermcourse pages 6-11)
A recent cohort study reports incidence estimates for classic lissencephaly of 11.7–40 per million births and cites substantial mortality burden (approximately 50% mortality by age 10 years). (proepper2026genespecificlongtermcourse pages 6-11)
The CLASP1 report explicitly involves a “multiplex consanguineous” family and demonstrates a recessive segregation pattern, supporting consanguinity as a practical risk factor for AR forms. (alsafh2024multiplexconsanguineousfamily pages 1-2)
MRI is foundational for diagnosis and for defining the malformation subtype. Kooshavar et al. recruited only children with MRI-defined malformations. (kooshavar2024diagnosticutilityof pages 1-3)
Kooshavar et al. (Brain Communications; accepted Feb 2024; advance access publication Feb 28, 2024) provides “real-world” yield data for exome sequencing in pediatric brain malformations, including lissencephaly and tubulinopathies:
Direct abstract quotes: - “The overall diagnostic yield for the clinical singleton exome sequencing was 36%, which increased to 43% after research follow-up.” (kooshavar2024diagnosticutilityof pages 1-3) - “The main source of increased diagnostic yield was the reanalysis of the singleton exome data to include newly discovered gene–disease associations. One additional diagnosis was made by trio exome sequencing.” (kooshavar2024diagnosticutilityof pages 1-3)
This cohort also provides subtype frequencies in their 102-patient series: polymicrogyria 36%, tubulinopathy 10%, lissencephaly 10%, among others. (kooshavar2024diagnosticutilityof pages 1-3)
The study required CMA first and excluded cases with pathogenic CNVs, highlighting the common diagnostic workflow: CMA → exome → research reanalysis/trio when indicated. (kooshavar2024diagnosticutilityof pages 1-3)
A 2026 prenatal MCD review quantifies the high de novo burden and limitations of routine prenatal screening: - “De novo mutations account for the majority of pathogenic genetic alterations identified in MCD (50.6%); up to 75.1% of pathogenic mutations cannot be detected by routine prenatal screening.” (hu2026prenataldiagnosisof pages 1-2)
Although not lissencephaly-specific, this is directly relevant to prenatal detection of lissencephaly-spectrum malformations because gyral/sulcal abnormalities are linked to microtubule/migration genes in that review. (hu2026prenataldiagnosisof pages 1-2)
Quantitative real-world morbidity and family impact includes high complication burdens (feeding difficulties, respiratory infections) and substantial caregiver HRQL impact. In one cohort, parental HRQL mean was 61.23 (SD 16.79) by PedsQL Family Impact Module. (proepper2026genespecificlongtermcourse pages 6-11)
There are no established disease-modifying therapies in the retrieved evidence set; care is multidisciplinary and supportive: - Antiseizure medications (illustrated by a TUBA1A case with infantile spasms treated with valproate and vigabatrin) (ren2024lissencephalycausedby pages 1-2) - Feeding and dysphagia management including tube feeding/PEG when needed (quantified in a cohort) (proepper2026genespecificlongtermcourse pages 6-11) - Respiratory therapy and infection management (proepper2026genespecificlongtermcourse pages 6-11) - Physiotherapy and other developmental therapies (proepper2026genespecificlongtermcourse pages 6-11)
In a lissencephaly cohort, “physiotherapy and respiratory therapy [were] considered the most effective,” and families used a median of eight supportive therapies per patient. (proepper2026genespecificlongtermcourse pages 6-11)
Based on management described: - Antiepileptic drug therapy (seizure management) (ren2024lissencephalycausedby pages 1-2) - Enteral feeding / tube feeding (proepper2026genespecificlongtermcourse pages 6-11) - Physiotherapy (proepper2026genespecificlongtermcourse pages 6-11) - Respiratory therapy (proepper2026genespecificlongtermcourse pages 6-11)
Primary prevention is generally not feasible for monogenic lissencephaly-spectrum disorders, but genetic counseling and reproductive options (prenatal diagnosis, preimplantation genetic testing) are practical prevention strategies once a familial pathogenic variant is known. This is supported indirectly by the emphasis on the importance of a precise genetic diagnosis for counseling and reproductive planning in genomic-diagnostic cohort work. (kooshavar2024diagnosticutilityof pages 1-3)
Evidence for naturally occurring non-human disease was not retrieved in this run.
Mechanistic validation in modern lissencephaly genetics increasingly uses functional neurodevelopmental assays and advanced transcriptomics: - The 2024 NDEL1 study used “single-cell RNA sequencing and spatial transcriptomic analysis” and in utero electroporation knockdown to test neuronal migration phenotypes. (tsai2024novellissencephalyassociatedndel1 pages 1-2)
This supports the use of mouse neurodevelopmental systems and multi-omic profiling as key current research implementations for lissencephaly-spectrum gene discovery and mechanism elucidation. (tsai2024novellissencephalyassociatedndel1 pages 1-2)
ClinicalTrials.gov includes an interventional study explicitly focused on genetic/transcriptomic diagnosis of lissencephalies: - NCT05185414 “Combining Exome and Transcriptome Data to Unravel the Genetic Basis of the Lissencephalies” (Universitair Ziekenhuis Brussel; enrollment 50; status unknown). (OpenTargets Search: lissencephaly)
| Item | Key details | Evidence/PMID/DOI/URL | Publication date | Context citation id(s) |
|---|---|---|---|---|
| Disease spectrum / definition | Lissencephaly spectrum disorders are malformations of cortical development caused chiefly by defective neuronal migration; the spectrum includes agyria, pachygyria, and subcortical band heterotopia (SBH, “double cortex”). Clinical comorbidity commonly includes developmental delay/intellectual disability, hypotonia progressing to spasticity, and seizures. | Uctepe et al., Eur J Hum Genet 2024, DOI: 10.1038/s41431-023-01461-2, https://doi.org/10.1038/s41431-023-01461-2 | 2024-10 | (uctepe2024biallelictruncatingvariants pages 1-2) |
| Spectrum subtypes / pathology | Classic lissencephaly is linked to cortical dyslamination genes such as PAFAH1B1, DCX, ARX; cobblestone lissencephaly shows distinct neuropathology associated with glycosylation pathway genes such as POMGNT1, POMT1, POMT2. | Brock et al., systematic review; summarized neuropathology of genetically defined MCDs | n/a | (brockUnknownyearneuropathologyofgenetically pages 13-13) |
| Standardized disease concept | MONDO includes lissencephaly spectrum disorders = MONDO:0018838; Open Targets links high-confidence associated targets including DCX, PAFAH1B1, TUBA1A, ARX, RELN, CEP85L, LAMB1, MACF1. | Open Targets disease-target association, https://platform.opentargets.org | current platform query | (OpenTargets Search: lissencephaly) |
| Key genes / common established causes | The most common established genes across classic lissencephaly are PAFAH1B1 (LIS1) and DCX; major additional genes include TUBA1A, DYNC1H1, TUBG1, ARX, RELN, CEP85L, LAMB1, MACF1, KATNB1. | Open Targets; Proepper et al., Orphanet J Rare Dis 2026, DOI: 10.1186/s13023-026-04398-z, https://doi.org/10.1186/s13023-026-04398-z | 2026-05; platform current | (OpenTargets Search: lissencephaly, proepper2026genespecificlongtermcourse pages 6-11) |
| Inheritance pattern: AD / de novo | Many lissencephaly-spectrum disorders are autosomal dominant, often de novo, especially tubulinopathies. TUBA1A is reported as the most commonly mutated tubulin gene; “most cases” show de novo autosomal dominant inheritance. | Ren et al., Front Pediatr 2024, DOI: 10.3389/fped.2024.1367305, https://doi.org/10.3389/fped.2024.1367305 | 2024-05 | (ren2024lissencephalycausedby pages 1-2) |
| Inheritance pattern: X-linked | DCX is an X-linked cause: males often show classic lissencephaly, while females may show SBH/double cortex; mosaic/non-coding variation can yield milder phenotypes. | Gao et al., Heliyon 2023, DOI: 10.1016/j.heliyon.2023.e22323, https://doi.org/10.1016/j.heliyon.2023.e22323; Open Targets | 2023-11 | (OpenTargets Search: lissencephaly) |
| Inheritance pattern: AR | Recessive forms are increasingly recognized, including CASP2, CLASP1, TUBGCP2, and earlier CRADD/PIDD1-related anterior-predominant LIS. | Uctepe et al. 2024; Alsafh et al. 2024; Yu et al. 2025 | 2024-10; 2024-08; 2025-02 | (uctepe2024biallelictruncatingvariants pages 1-2, alsafh2024multiplexconsanguineousfamily pages 1-2, yu2025tubgcp2variantscause pages 1-2) |
| Inheritance pattern: somatic mosaic | NDEL1 p.Arg105Pro was identified as a de novo somatic mosaic cause of pachygyria with or without SBH, establishing mosaic dynein-pathway disease within the lissencephaly spectrum. | Tsai et al., Acta Neuropathol 2024, DOI: 10.1007/s00401-023-02665-y, https://doi.org/10.1007/s00401-023-02665-y | 2024-01 | (tsai2024novellissencephalyassociatedndel1 pages 1-2) |
| Quantitative stat: exome diagnostic yield | In 102 children with brain malformations, singleton clinical exome had 36% diagnostic yield, increasing to 43% after research follow-up/reanalysis; one additional diagnosis came from trio exome. Lissencephaly represented 10% of the cohort, and the highest phenotype-based yields were for cobblestone malformation, tubulinopathy, and lissencephaly. | Kooshavar et al., Brain Communications 2024, DOI: 10.1093/braincomms/fcae056, https://doi.org/10.1093/braincomms/fcae056 | 2024-02-28 | (kooshavar2024diagnosticutilityof pages 1-3) |
| Quantitative stat: malformation subtype mix | Among the Kooshavar cohort, commonest subtypes were polymicrogyria 36%, pontocerebellar hypoplasia 14%, periventricular nodular heterotopia 11%, tubulinopathy 10%, lissencephaly 10%, cortical dysplasia 9%. | Kooshavar et al., Brain Communications 2024, DOI: 10.1093/braincomms/fcae056, https://doi.org/10.1093/braincomms/fcae056 | 2024-02-28 | (kooshavar2024diagnosticutilityof pages 1-3, kooshavar2024diagnosticutilityof pages 3-4) |
| Quantitative stat: recurrent gene in diagnostics | In the Kooshavar series, the most frequent genetic diagnosis was TUBA1A. | Kooshavar et al., Brain Communications 2024, DOI: 10.1093/braincomms/fcae056, https://doi.org/10.1093/braincomms/fcae056 | 2024-02-28 | (kooshavar2024diagnosticutilityof pages 1-3) |
| Quantitative stat: prenatal genetics | In prenatal MCD literature synthesized by Hu et al., de novo mutations accounted for 50.6% of pathogenic alterations, and up to 75.1% of pathogenic mutations were not detectable by routine prenatal screening; proliferation-phase abnormalities were 62.9% of prenatal MCD phenotypes. | Hu et al., Biomedicines 2026, DOI: 10.3390/biomedicines14010107, https://doi.org/10.3390/biomedicines14010107 | 2026-01 | (hu2026prenataldiagnosisof pages 1-2) |
| Quantitative stat: incidence / mortality | A recent long-term cohort summary cites classic lissencephaly incidence of 11.7–40 per million births, infantile epileptic spasms syndrome in 57%, and approximately 50% mortality by age 10 years. | Proepper et al., Orphanet J Rare Dis 2026, DOI: 10.1186/s13023-026-04398-z, https://doi.org/10.1186/s13023-026-04398-z | 2026-05 | (proepper2026genespecificlongtermcourse pages 6-11) |
| Quantitative stat: prenatal abnormalities and age at recognition | In the Proepper cohort, prenatal abnormalities were seen in 14/37 (38%) of PAFAH1B1/LIS1 and 2/5 (40%) of DCX cases; median age at suspected diagnosis was 5 months for LIS1-related and 9 months for DCX-related disease. | Proepper et al., Orphanet J Rare Dis 2026, DOI: 10.1186/s13023-026-04398-z, https://doi.org/10.1186/s13023-026-04398-z | 2026-05 | (proepper2026genespecificlongtermcourse pages 6-11, proepper2026genespecificlongtermcourse pages 11-16) |
| Quantitative stat: complications / feeding / respiratory | In the Proepper cohort, frequent complications included recurrent respiratory infections 14/38 (37%) in LIS1 and 1/4 (25%) in DCX; dysphagia/vomiting 23/37 (62%) in LIS1 and 2/4 (50%) in DCX; tube feeding required in 15/38 (40%) in LIS1 and 1/5 (20%) in DCX. | Proepper et al., Orphanet J Rare Dis 2026, DOI: 10.1186/s13023-026-04398-z, https://doi.org/10.1186/s13023-026-04398-z | 2026-05 | (proepper2026genespecificlongtermcourse pages 6-11) |
| Quantitative stat: supportive care burden / QoL | Families reported a median of 8 supportive therapies per patient (range 1–17); physiotherapy and respiratory therapy were rated most effective. Parental HRQL mean was 61.23 (SD 16.79), indicating substantial caregiver burden. | Proepper et al., Orphanet J Rare Dis 2026, DOI: 10.1186/s13023-026-04398-z, https://doi.org/10.1186/s13023-026-04398-z | 2026-05 | (proepper2026genespecificlongtermcourse pages 6-11) |
| Recent expansion: NDEL1 | First lissencephaly-associated NDEL1 variant: two unrelated patients with pachygyria ± SBH carried the same de novo somatic mosaic p.Arg105Pro; mechanism implicated failure of nucleokinesis via disrupted NDEL1–LIS1 interaction. | Tsai et al., Acta Neuropathol 2024, DOI: 10.1007/s00401-023-02665-y, https://doi.org/10.1007/s00401-023-02665-y | 2024-01 | (tsai2024novellissencephalyassociatedndel1 pages 1-2) |
| Recent expansion: CASP2 | CASP2 added to the PIDDosome-related lissencephaly genes: 7 patients from 5 families with biallelic truncating/splice variants had anterior/frontotemporal LIS and pachygyria resembling CRADD/PIDD1 disease. | Uctepe et al., Eur J Hum Genet 2024, DOI: 10.1038/s41431-023-01461-2, https://doi.org/10.1038/s41431-023-01461-2 | 2024-10 | (uctepe2024biallelictruncatingvariants pages 1-2) |
| Recent expansion: CLASP1 | CLASP1 emerged as a candidate recessive lissencephaly gene in a multiplex consanguineous family; 3 siblings had homozygous c.4442G>A p.Arg1481His with classic lissencephaly, microcephaly, severe developmental delay, and early refractory epilepsy. | Alsafh et al., Neurology Genetics 2024, DOI: 10.1212/NXG.0000000000200172, https://doi.org/10.1212/NXG.0000000000200172 | 2024-08 | (alsafh2024multiplexconsanguineousfamily pages 1-2) |
| Diagnostic approach: imaging | Brain MRI remains the core diagnostic modality for defining the malformation pattern and guiding gene prioritization. Recognizable signatures include anterior/frontotemporal LIS in CASP2/CRADD/PIDD1, posterior>anterior classic LIS plus thin splenium/pontine hypoplasia in CLASP1, and pachygyria ± SBH in mosaic NDEL1. | Uctepe et al. 2024; Alsafh et al. 2024; Tsai et al. 2024 | 2024 | (uctepe2024biallelictruncatingvariants pages 1-2, alsafh2024multiplexconsanguineousfamily pages 1-2, tsai2024novellissencephalyassociatedndel1 pages 1-2) |
| Diagnostic approach: genetics | Recommended workflow supported by recent evidence: CMA first to detect CNVs; then exome sequencing; then periodic reanalysis because reanalysis contributed more to added diagnoses than trio expansion in a real-world MCD cohort. | Kooshavar et al., Brain Communications 2024, DOI: 10.1093/braincomms/fcae056, https://doi.org/10.1093/braincomms/fcae056 | 2024-02-28 | (kooshavar2024diagnosticutilityof pages 1-3, kooshavar2024diagnosticutilityof pages 3-4) |
| Diagnostic approach: prenatal | For suspected fetal cortical malformations, fetal neurosonography + fetal MRI + NGS/WES are increasingly emphasized; routine prenatal screens miss many pathogenic variants. | Hu et al., Biomedicines 2026, DOI: 10.3390/biomedicines14010107, https://doi.org/10.3390/biomedicines14010107 | 2026-01 | (hu2026prenataldiagnosisof pages 1-2) |
| Management / supportive therapies | No disease-modifying therapy is established; current care is multidisciplinary and supportive: antiepileptic therapy, feeding support including tube feeding/PEG when needed, physiotherapy, respiratory therapy, developmental therapies, and caregiver support. Physiotherapy and respiratory therapy were reported as most effective in family surveys. | Proepper et al., Orphanet J Rare Dis 2026, DOI: 10.1186/s13023-026-04398-z, https://doi.org/10.1186/s13023-026-04398-z; Ren et al. 2024 | 2026-05; 2024-05 | (proepper2026genespecificlongtermcourse pages 6-11, ren2024lissencephalycausedby pages 1-2) |
Table: This table condenses high-yield definitions, genetics, quantitative clinical statistics, recent gene discoveries, and current diagnostic/management points for lissencephaly spectrum disorders. It is useful as a structured reference for building a disease knowledge-base entry with linked evidence.
1) Diagnostic genomics evidence in real-world cohorts (2024): singleton exome yield 36% rising to 43% with reanalysis; reanalysis is a major contributor to additional diagnoses, and TUBA1A is a frequent diagnosis. (kooshavar2024diagnosticutilityof pages 1-3) 2) New mechanistic gene association with modern multi-omics (2024): somatic mosaic NDEL1 p.Arg105Pro linked to nucleokinesis failure via disrupted LIS1 binding, with scRNA-seq/spatial transcriptomics and functional migration assays. (tsai2024novellissencephalyassociatedndel1 pages 1-2) 3) Expansion of AR lissencephaly genes (2024): CASP2 biallelic truncating variants implicate the PIDDosome/caspase-2 axis in cortical development; CLASP1 is a candidate AR lissencephaly gene in a consanguineous family, supporting microtubule minus-end stabilization biology in disease. (uctepe2024biallelictruncatingvariants pages 1-2, alsafh2024multiplexconsanguineousfamily pages 1-2)
References
(OpenTargets Search: lissencephaly): Open Targets Query (lissencephaly, 25 results). Buniello, A. et al. (2025). Open Targets Platform: facilitating therapeutic hypotheses building in drug discovery. Nucleic Acids Research.
(uctepe2024biallelictruncatingvariants pages 1-2): Eyyup Uctepe, Barbara Vona, Fatma Nisa Esen, F. Mujgan Sonmez, Thomas Smol, Sait Tümer, Hanifenur Mancılar, Dilan Ece Geylan Durgun, Odile Boute, Meysam Moghbeli, Ehsan Ghayoor Karimiani, Narges Hashemi, Behnoosh Bakhshoodeh, Hyung Goo Kim, Reza Maroofian, and Ahmet Yesilyurt. Bi-allelic truncating variants in casp2 underlie a neurodevelopmental disorder with lissencephaly. European Journal of Human Genetics, 32:52-60, Oct 2024. URL: https://doi.org/10.1038/s41431-023-01461-2, doi:10.1038/s41431-023-01461-2. This article has 13 citations and is from a domain leading peer-reviewed journal.
(alsafh2024multiplexconsanguineousfamily pages 1-2): Rawan Alsafh, Amal Alhashem, Aly Elsyed, Zafer Yüksel, Kalthoum Graiess-Tlili, Khalid Hundallah, Farah Thabet, and Brahim Tabarki. Multiplex consanguineous family highlights clasp1 as a candidate gene for lissencephaly. Aug 2024. URL: https://doi.org/10.1212/nxg.0000000000200172, doi:10.1212/nxg.0000000000200172. This article has 6 citations.
(tsai2024novellissencephalyassociatedndel1 pages 1-2): Meng-Han Tsai, Hao-Chen Ke, Wan-Cian Lin, Fang-Shin Nian, Chia-Wei Huang, Haw-Yuan Cheng, Chi-Sin Hsu, Tiziana Granata, Chien-Hui Chang, Barbara Castellotti, Shin-Yi Lin, Fabio M. Doniselli, Cheng-Ju Lu, Silvana Franceschetti, Francesca Ragona, Pei-Shan Hou, Laura Canafoglia, Chien-Yi Tung, Mei-Hsuan Lee, Won-Jing Wang, and Jin-Wu Tsai. Novel lissencephaly-associated ndel1 variant reveals distinct roles of nde1 and ndel1 in nucleokinesis and human cortical malformations. Acta Neuropathologica, Jan 2024. URL: https://doi.org/10.1007/s00401-023-02665-y, doi:10.1007/s00401-023-02665-y. This article has 11 citations and is from a highest quality peer-reviewed journal.
(kooshavar2024diagnosticutilityof pages 1-3): Daniz Kooshavar, David J Amor, Kirsten Boggs, Naomi Baker, Christopher Barnett, Michelle G de Silva, Samantha Edwards, Michael C Fahey, Justine E Marum, Penny Snell, Kiymet Bozaoglu, Kate Pope, Shekeeb S Mohammad, Kate Riney, Rani Sachdev, Ingrid E Scheffer, Sarah Schenscher, John Silberstein, Nicholas Smith, Melanie Tom, Tyson L Ware, Paul J Lockhart, and Richard J Leventer. Diagnostic utility of exome sequencing followed by research reanalysis in human brain malformations. Brain Communications, Feb 2024. URL: https://doi.org/10.1093/braincomms/fcae056, doi:10.1093/braincomms/fcae056. This article has 6 citations and is from a peer-reviewed journal.
(pavone2023casereportstructural pages 1-2): Piero Pavone, Pasquale Striano, Giovanni Cacciaguerra, Simona Domenica Marino, Enrico Parano, Xena Giada Pappalardo, Raffaele Falsaperla, and Martino Ruggieri. Case report: structural brain abnormalities in tuba1a-tubulinopathies: a narrative review. Frontiers in Pediatrics, Sep 2023. URL: https://doi.org/10.3389/fped.2023.1210272, doi:10.3389/fped.2023.1210272. This article has 7 citations.
(ren2024lissencephalycausedby pages 1-2): Sijing Ren, Yu Kong, Ruihan Liu, Qiu-bo Li, Xuehua Shen, and Qing-xia Kong. Lissencephaly caused by a de novo mutation in tubulin tuba1a: a case report and literature review. Frontiers in Pediatrics, May 2024. URL: https://doi.org/10.3389/fped.2024.1367305, doi:10.3389/fped.2024.1367305. This article has 5 citations.
(proepper2026genespecificlongtermcourse pages 6-11): Christiane R. Proepper, Lisa-Maria Schwarz, Sofia M. Schuetz, Katja von Au, Thomas Bast, Nathalie Beaud, Ingo Borggraefe, Friedrich Bosch, Melanie Busse, Jena Chung, Otfried Debus, Katharina Diepold, Thomas Fries, Gero von Gersdorff, Martin Haeussler, Andreas Hahn, Till Hartlieb, Ralf Heiming, Peter Herkenrath, Gerhard Kluger, Jonas H. Kreth, Gerhard Kurlemann, Peter Moeller, Deborah J. Morris-Rosendahl, Axel Panzer, Heike Philippi, Sophia Ruegner, Carolina Toepfer, Silvia Vieker, Adelheid Wiemer-Kruel, Anika Winter, Gerhard Schuierer, Ute Hehr, and Tobias Geis. Gene-specific long-term course, neurodevelopmental outcome and quality of life in patients with lis1/pafah1b1-, dcx-, dync1h1-, tuba1a- and tubg1-related lissencephaly. Orphanet Journal of Rare Diseases, May 2026. URL: https://doi.org/10.1186/s13023-026-04398-z, doi:10.1186/s13023-026-04398-z. This article has 0 citations and is from a peer-reviewed journal.
(hu2026prenataldiagnosisof pages 1-2): Jinhua Hu, Xiaogang Xu, Ping Jiang, Ruibin Huang, Jiani Yuan, Long Lu, and Jin Han. Prenatal diagnosis of malformations of cortical development: a review of genetic and imaging advances. Biomedicines, 14:107, Jan 2026. URL: https://doi.org/10.3390/biomedicines14010107, doi:10.3390/biomedicines14010107. This article has 1 citations.
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(yu2025tubgcp2variantscause pages 1-2): Tao Yu, Miao Yu, Xueyan Liu, and Hua Wang. Tubgcp2 variants cause lissencephaly spectrum disorders: a case report and literature review. Frontiers in Pediatrics, Feb 2025. URL: https://doi.org/10.3389/fped.2025.1476390, doi:10.3389/fped.2025.1476390. This article has 1 citations.
(kooshavar2024diagnosticutilityof pages 3-4): Daniz Kooshavar, David J Amor, Kirsten Boggs, Naomi Baker, Christopher Barnett, Michelle G de Silva, Samantha Edwards, Michael C Fahey, Justine E Marum, Penny Snell, Kiymet Bozaoglu, Kate Pope, Shekeeb S Mohammad, Kate Riney, Rani Sachdev, Ingrid E Scheffer, Sarah Schenscher, John Silberstein, Nicholas Smith, Melanie Tom, Tyson L Ware, Paul J Lockhart, and Richard J Leventer. Diagnostic utility of exome sequencing followed by research reanalysis in human brain malformations. Brain Communications, Feb 2024. URL: https://doi.org/10.1093/braincomms/fcae056, doi:10.1093/braincomms/fcae056. This article has 6 citations and is from a peer-reviewed journal.
(proepper2026genespecificlongtermcourse pages 11-16): Christiane R. Proepper, Lisa-Maria Schwarz, Sofia M. Schuetz, Katja von Au, Thomas Bast, Nathalie Beaud, Ingo Borggraefe, Friedrich Bosch, Melanie Busse, Jena Chung, Otfried Debus, Katharina Diepold, Thomas Fries, Gero von Gersdorff, Martin Haeussler, Andreas Hahn, Till Hartlieb, Ralf Heiming, Peter Herkenrath, Gerhard Kluger, Jonas H. Kreth, Gerhard Kurlemann, Peter Moeller, Deborah J. Morris-Rosendahl, Axel Panzer, Heike Philippi, Sophia Ruegner, Carolina Toepfer, Silvia Vieker, Adelheid Wiemer-Kruel, Anika Winter, Gerhard Schuierer, Ute Hehr, and Tobias Geis. Gene-specific long-term course, neurodevelopmental outcome and quality of life in patients with lis1/pafah1b1-, dcx-, dync1h1-, tuba1a- and tubg1-related lissencephaly. Orphanet Journal of Rare Diseases, May 2026. URL: https://doi.org/10.1186/s13023-026-04398-z, doi:10.1186/s13023-026-04398-z. This article has 0 citations and is from a peer-reviewed journal.