Spina Bifida Cystica: Comprehensive Disease-Characteristics Report

Executive summary

Spina bifida cystica is a congenital open or sac-forming spinal dysraphism caused by failed closure of the caudal neural tube during the first four embryonic weeks. Its principal forms are myelomeningocele/meningomyelocele, in which neural tissue and meninges protrude through a vertebral defect, and meningocele, in which the sac contains meninges and cerebrospinal fluid without exposed spinal cord. Myelomeningocele (MMC) is the clinically dominant and most severe survivable form. It produces lesion-level-dependent paralysis and sensory loss, neurogenic bladder and bowel, orthopedic deformity, Chiari II malformation, hydrocephalus, and variable neurocognitive and psychosocial disability. It is congenital and lifelong rather than degenerative, although hydrocephalus, shunt failure, tethered cord, renal injury, skin breakdown, pain, and musculoskeletal problems can cause secondary deterioration.

Current understanding is that most nonsyndromic disease is complex, multifactorial, polygenic, and incompletely penetrant. The strongest recent genetic result is the 2024 identification of the recurrent 22q11.2 deletion, with CRKL haploinsufficiency as a major candidate mechanism and maternal folate status modifying penetrance in mice. Preventive folic acid, prenatal ultrasound/MRI, multidisciplinary lifelong care, and—in selected pregnancies—prenatal repair are established real-world interventions. Prenatal repair improves motor and hydrocephalus-related outcomes but is not curative and carries maternal and prematurity risks. Placental mesenchymal-stromal-cell augmentation of fetal repair remains investigational.

Table: This compact evidence matrix summarizes high-value recent and foundational studies across genetics, prevention, surgery, prognosis, rehabilitation, and experimental therapy for spina bifida cystica/myelomeningocele. It is useful for rapidly mapping claims to quantitative evidence and source URLs.

1. Disease information

Definition and classification

Spina bifida cystica denotes a visible cystic/open defect produced by incomplete formation of the posterior vertebral arches and neural-tube coverings. In MMC, spinal cord/neural placode and meninges protrude through the defect; in meningocele, only meninges and cerebrospinal fluid protrude. “Open spina bifida,” “spina bifida aperta,” “myelomeningocele,” “meningomyelocele,” “myeloschisis,” and “open neural-tube defect” are common overlapping terms, although myeloschisis specifically describes a flat, open neural placode without a well-formed sac. MMC is described in recent primary literature as “one of the most severe forms of neural tube defects” and “the most frequent structural birth defect of the central nervous system.” (vong2024riskofmeningomyelocele pages 1-2)

This entity must be distinguished from spina bifida occulta/closed spinal dysraphism, in which skin covers the defect and the phenotype may involve lipoma, dermal sinus, split cord, or tethering rather than an exposed placode.

Identifiers

• MONDO: MONDO:0017069, spina bifida cystica. The broader parent is MONDO:0008449, spina bifida.
• MeSH: D008591, Meningomyelocele; parent D009436, Neural Tube Defects. ClinicalTrials.gov uses D008591 for the open MMC phenotype. (NCT04027374 chunk 2)
• ICD-10: Q05.-, spina bifida; subcodes specify cervical, thoracic, lumbar, or sacral level and presence/absence of hydrocephalus.
• ICD-11: LA02, spina bifida, with extension coding for anatomy and associated manifestations.
• OMIM: MMC/spina bifida is genetically heterogeneous and generally does not have one definitive monogenic OMIM disease entry. Gene-specific or syndromic NTD entries should be represented separately rather than assigning one causal OMIM number to all cystic spina bifida.
• SNOMED CT: concepts include myelomeningocele and meningocele; local terminology-server verification is recommended before production ingestion.

The evidence summarized here is predominantly aggregated disease-level evidence from registries, cohorts, trials, and genomic studies—not an individual EHR. Individual-patient sequencing and clinical observations contribute to those aggregated studies.

2. Etiology, risk, protection, and gene–environment interaction

Causal framework

The upstream developmental event is failed neurulation, normally completed approximately 21–28 days after fertilization. Failure of caudal neuropore closure leaves neural tissue exposed. A widely accepted two-hit model proposes: (1) primary failure of closure and abnormal cord development; then (2) progressive chemical and mechanical injury from amniotic fluid and fetal movement. A fetal-surgery protocol states that without protective coverage, “secondary destruction of the exposed neural tissue by trauma or amniotic fluid may occur throughout gestation.” (risova2024preconceptionalandpericonceptional pages 1-3, NCT04027374 chunk 1)

Genetic susceptibility

Most isolated MMC is non-Mendelian. Heritability has been estimated as high as 70%, but this does not imply that 70% of patients carry one identifiable pathogenic variant. Rare variants, polygenic background, maternal and fetal genotypes, epigenetic state, and exposures interact. (vong2024riskofmeningomyelocele pages 1-2, aguiarpulido2021systemsbiologyanalysis pages 1-3)

Important susceptibility pathways and genes include:

• Noncanonical WNT/planar-cell-polarity and convergent extension: VANGL1, VANGL2, CELSR1, SCRIB, DACT1, PARD3 and related genes. Rare/ultrarare WNT-pathway variants occur in an estimated 1–3% of patients, but many are susceptibility alleles rather than fully penetrant monogenic causes. (vong2024riskofmeningomyelocele pages 1-2)
• Apical constriction/cytoskeletal morphogenesis: SHROOM3.
• Folate/one-carbon metabolism: MTHFR, MTR, MTRR, MTHFD1, SLC25A32.
• Developmental transcription and epithelial regulation: TBXT, GRHL2, GRHL3.
• Structural variation: 22q11.2 deletion, discussed below.

Open Targets lists associations for MTRR, MTHFR, VANGL1, SLC25A32, MTR, VANGL2, PARD3, SCRIB, DACT1, SHROOM3, MTHFD1, and TBXT. These are association-level targets and should not all be labelled clinically proven causal genes. (OpenTargets Search: spina bifida,myelomeningocele)

Environmental and maternal risks

Established or repeatedly supported risks include insufficient periconceptional folate, low vitamin B12, pregestational diabetes, maternal obesity, hyperthermia/fever during neurulation, and folate-antagonist or antiseizure drugs—especially valproate. Smoking, pesticides, arsenic, polycyclic aromatic hydrocarbons, selected infections, and fumonisin mycotoxin exposure have varying, generally less definitive evidence. Recent literature explicitly identifies maternal diabetes, valproate, and fumonisin as risk-enhancing exposures. (risova2024preconceptionalandpericonceptional pages 1-3, vong2024riskofmeningomyelocele pages 1-2)

There is no established infectious organism that directly causes spina bifida cystica; infection is a possible maternal exposure or a downstream complication, not a transmissible etiology. Alcohol and smoking avoidance is prudent for general fetal health, but their spina-bifida-specific effect is weaker than folate, diabetes, obesity, hyperthermia, and valproate evidence.

Protective factors

The principal proven environmental protection is adequate periconceptional folate. Randomized trials summarized in a review published 31 December 2024 found nearly 80% reduction in NTD incidence, supporting 400 µg folic acid daily for women capable of pregnancy. High-risk regimens commonly use 4–5 mg/day under clinician supervision, beginning before conception, because closure occurs before many pregnancies are recognized. Food fortification reduces population prevalence and addresses unplanned pregnancy. (risova2024preconceptionalandpericonceptional pages 1-3)

No reproducible “protective allele” is ready for clinical use. Likewise, no exercise, vaccine, or postconception lifestyle intervention can reverse a closure defect once formed.

Direct gene–environment evidence: 22q11.2–CRKL–folate

In 715 parent–offspring trios, six patients had 22q11.2 deletions: four de novo and two inherited. Frequency was 0.839% versus 0.0368% in gnomAD controls, OR 22.98 (95% CI 6.47–81.61). An independent cohort of 1,522 deletion carriers contained eight MMC cases, implying 12.28- to 15.54-fold excess risk. CRKL was strongly expressed in developing neural tube; Crkl loss reproduced NTDs in mice, and folate deficiency worsened penetrance and expressivity, while supplementation partly alleviated risk. The authors’ exact conclusion was: “the common 22q11.2 deletion confers substantial meningomyelocele risk, which is partially alleviated by folate supplementation.” This is unusually strong evidence linking human structural variation, developmental expression, animal function, and environmental modification. (vong2024riskofmeningomyelocele pages 2-4, vong2024riskofmeningomyelocele pages 1-2)

3. Phenotypes

Phenotypes are present at birth, although prenatal imaging can identify them earlier. Severity is highly variable and is driven mainly by anatomical/functional lesion level, preservation of neural tissue, hydrocephalus/Chiari II, and complications.

• Open/cystic spinal lesion—congenital, usually lumbosacral; severity ranges from isolated meningocele to exposed MMC/myeloschisis. Suggested HPO: Myelomeningocele (HP:0002475); Meningocele; Spina bifida.
• Lower-limb weakness or paralysis and sensory loss—congenital, generally stable at baseline but may worsen with tethering, shunt dysfunction, syrinx, or orthopedic complications. HPO: Paraparesis, Paraplegia, Lower-limb muscle weakness, Hyporeflexia, Impaired pain sensation.
• Neurogenic bladder—very common in MMC; may cause retention, incontinence, vesicoureteral reflux, recurrent UTI, hydronephrosis, renal scarring, and chronic kidney disease. HPO: Neurogenic bladder (HP:0000011), Urinary incontinence, Recurrent UTI, Hydronephrosis.
• Neurogenic bowel/constipation and fecal incontinence—reported in approximately 90% in one clinical synthesis, although frequency depends on definition. HPO: Neurogenic bowel, Constipation, Fecal incontinence. (mathew2018antenataldiagnosismaternal pages 14-17)
• Chiari II malformation and hydrocephalus—most severe MMC cases have Chiari II; hindbrain herniation was reported in >80% in one synthesis. Consequences include shunt dependence, brainstem dysfunction, swallowing/respiratory problems, and cognitive effects. HPO: Chiari malformation type II (HP:0002308), Hydrocephalus (HP:0000238), Ventriculomegaly.
• Orthopedic manifestations—clubfoot, hip dislocation/subluxation, scoliosis/kyphosis, contractures, reduced bone density and fractures. HPO: Talipes equinovarus, Scoliosis, Kyphosis, Hip dislocation, Joint contracture.
• Tethered cord—often secondary to repair; clinically relevant when accompanied by new pain, weakness, deformity, gait or bladder deterioration. HPO: Tethered cord.
• Skin and mobility complications—pressure injury, neuropathic ulceration, obesity, reduced fitness, and wheelchair dependence. HPO: Pressure ulcer, Abnormality of gait, Inability to walk.
• Neurocognitive/behavioral phenotype—learning difficulties, executive dysfunction, impaired attention and visuospatial/mathematical skills can occur, especially with hydrocephalus and intracranial anomalies. Global intellectual disability is not obligatory. (houtrow2020prenatalrepairof pages 1-2)
• Pain, depression, anxiety, social isolation, and sexual dysfunction contribute substantially to adult burden. A claims cohort combining adults with cerebral palsy or spina bifida found pain disorders in 55.9% versus 35.2% of controls; this estimate is not MMC-specific and should not be used as an isolated-MMC frequency.

Quality-of-life effects include dependence in bathing, dressing, toileting, catheterization, mobility, transportation, meal preparation, and financial management. Dependence is greater with hydrocephalus and lesions above L2. A 2024 review found that camp-based interventions, Cognitive Orientation to Daily Occupational Performance, and occupation-based therapy improved independence, but the intervention literature remains heterogeneous. (ferreira2024interventionstoimprove pages 1-3)

4. Genetic and molecular information

Variant interpretation

There is no universal diagnostic “spina bifida gene panel” with high yield for isolated MMC. Most reported variants are germline susceptibility alleles, rare variants, or copy-number changes with incomplete penetrance. Somatic mutation is not an established mechanism.

• 22q11.2 deletion: pathogenic structural germline variant; inherited or de novo. In the 2024 cohort, 4/6 were de novo and 2/6 inherited from clinically unrecognized carriers, demonstrating incomplete penetrance. The minimal consensus interval contained ten protein-coding genes, with CRKL prioritized. (vong2024riskofmeningomyelocele pages 2-4)
• PCP variants: predominantly rare missense or loss-of-function susceptibility variants; classification may range from pathogenic in a defined syndrome to VUS/risk allele in isolated MMC. Each variant requires ClinVar/ClinGen and segregation review.
• MTHFR C677T and A1298C: common functional polymorphisms, not deterministic pathogenic variants. Approximately 60–70% of the general population carries at least one of these variants; around 10% is homozygous or compound heterozygous. These figures must not be interpreted as carrier frequencies for spina bifida. (risova2024preconceptionalandpericonceptional pages 1-3)
• Bangladesh study: among 112 affected children, 121 controls, 272 mothers, and 128 trios, transmission disequilibrium identified rs140199800 in SULT1C2 (P=1.9×10⁻⁷), rs45580033 in ASB2 (P=4.2×10⁻¹⁰), and rs75426652 in LHPP (P=7.2×10⁻¹⁴). Case–control models found no genome-wide-significant variants; replication is required. (tindula2024genome‐wideanalysisof pages 1-3)
• Regulatory variation: a 2023 mouse study identified an approximately 4-kb LTR insertion about 300 bp upstream of Grhl2, causing overexpression and spina bifida/encephalocele. Rare human upstream variants were found in only a small number of cases and remain candidates rather than proven clinical variants. (cranesmith2023anoncodinginsertional pages 1-2)

A WGS systems-biology study of 149 cases and 149 ancestry-matched controls found no single definitive gene after multiple-testing correction. Machine learning identified 439 discriminatory genes and pathway enrichment in carbon metabolism, inflammation/innate immunity, cytoskeletal regulation, and transcription; hold-out AUROC was 0.78. This is computational association evidence, not a validated diagnostic classifier. (aguiarpulido2021systemsbiologyanalysis pages 1-3)

Epigenetics and molecular profiling

Folate participates in one-carbon transfer, nucleotide synthesis, DNA repair, and methylation. Deficiency may cause DNA hypomethylation, impaired thymidylate synthesis, uracil misincorporation, and genomic instability. The exact folate-protective mechanism nevertheless remains unresolved. (risova2024preconceptionalandpericonceptional pages 1-3)

RNA-seq of five fibroblast lines from 22q11.2-deletion/MMC patients showed reduced expression largely within the deleted interval. Murine spatial transcriptomics and human embryonic single-nucleus RNA-seq demonstrated CRKL, PI4KA, and LZTR1 expression in neural-tube progenitors, neurons, and neural crest. These data prioritize mechanisms but do not constitute a clinical biomarker. (vong2024riskofmeningomyelocele pages 2-4)

NCT04027374 prospectively examined neonatal saliva DNA/RNA after fetal repair, measuring methylation of stress-regulation genes NR3C1 and FKBP5. It completed with 70 participants, but the retrieved registry did not provide definitive posted results; it should be cited as exploratory procedural-stress epigenomics, not disease-causal evidence. (NCT04027374 chunk 1, NCT04027374 chunk 2)

No validated diagnostic proteomic, metabolomic, lipidomic, single-cell, spatial, or liquid-biopsy signature is currently used in routine MMC care.

5. Environmental information

The critical exposure window is preconception through approximately day 28 after fertilization. Relevant chemical entities include folic acid (CHEBI:27470), folate, vitamin B12/cobalamin, valproic acid (CHEBI:39867), and fumonisin B1. Maternal glycemic control, healthy preconception weight, medication review, avoidance of hyperthermia, and adequate nutrition are actionable. Occupational/toxicant associations are plausible but generally lack the causal strength of folate deficiency, diabetes, obesity, and valproate. There is no zoonotic, contagious, or vaccine-preventable cause.

6. Mechanism and pathophysiology

Causal chain

1. Upstream susceptibility: fetal and maternal variants/CNVs, altered PCP-WNT, epithelial polarity, cytoskeletal/apical constriction, transcription, folate/one-carbon metabolism, and relevant exposures.
2. Failed neurulation: defective convergent extension and dorsolateral bending/apical constriction prevent caudal neural-fold fusion during weeks 3–4.
3. Open neural placode: vertebral arches, meninges, muscle, and skin fail to cover the cord.
4. Secondary fetal injury: exposed neural tissue undergoes chemical and mechanical injury, neuronal loss, gliosis, and progressive loss of motor/sensory function.
5. CSF/hindbrain consequences: leakage and altered craniospinal dynamics contribute to Chiari II hindbrain herniation, impaired CSF flow, ventriculomegaly, and hydrocephalus.
6. Clinical manifestations: segmental paralysis/sensory loss; autonomic denervation causes neurogenic bladder and bowel; muscle imbalance causes clubfoot, hip deformity, scoliosis and contractures; hydrocephalus and cerebral anomalies contribute to learning/executive deficits.
7. Downstream lifelong injury: shunt failure/infection, tethering, recurrent UTI and high bladder pressure, renal damage, pressure injury, pain, obesity and psychosocial stress.

Suggested mechanism ontologies

• GO biological process: neural tube closure; neural fold formation; convergent extension involved in neural plate elongation; planar cell polarity pathway; Wnt signaling; actin-cytoskeleton organization; epithelial-cell apical constriction; folic-acid metabolic process; one-carbon metabolic process; DNA methylation; neurogenesis; inflammatory response.
• Cell Ontology: neuroepithelial cell/neural progenitor cell; neuron; neural crest cell; radial glial cell; astrocyte; oligodendrocyte-lineage cell; ependymal cell; choroid-plexus epithelial cell; skeletal myocyte; urothelial cell.
• GO cellular component: adherens junction, apical plasma membrane, actin cytoskeleton, nucleus/chromatin, mitochondrion. These are pathway-relevant compartments; no single organelle defect defines MMC.

The immune system is not the primary cause, although inflammation appears in systems-level genomic enrichment and contributes downstream to exposed-tissue injury, shunt infection, UTI, and chronic wounds. (aguiarpulido2021systemsbiologyanalysis pages 1-3)

7. Anatomical structures affected

The primary site is the caudal neural tube and posterior vertebral column, most often lumbar/lumbosacral. Affected structures include spinal cord/neural placode, spinal nerve roots, meninges, vertebral arches, paraspinal muscle and skin. Suggested terms include UBERON:0002240 spinal cord, vertebral column, lumbar spinal cord, sacral spinal cord, meninges, skin of back, and skeletal muscle tissue.

Secondary structures include cerebellum and hindbrain/brainstem in Chiari II, cerebral ventricles and CSF pathways, lower-limb peripheral nerves and muscle, hips/knees/feet/spine, urinary bladder, ureters and kidneys, colon/rectum and pelvic floor. Lesions are midline, not meaningfully unilateral; neurological effects are commonly bilateral but may be asymmetric.

8. Temporal development

The initiating defect is embryonic and acute within the neurulation window, but the phenotype evolves through gestation because exposed neural tissue can sustain progressive injury. Prenatal diagnosis usually occurs during first- or second-trimester screening. After birth, the disease course is chronic and lifelong.

There is no spontaneous remission of the anatomical defect. Repair closes/protects tissue but does not regenerate all lost neural function. Critical windows are: preconception to day 28 for prevention; midgestation for fetal-repair evaluation; the first 24–48 hours after birth for closure when prenatal repair was not performed; infancy for hydrocephalus surveillance; growth periods for tethering and orthopedic progression; and adolescence for transition to adult self-management.

9. Inheritance and population

Inheritance

Most isolated disease follows multifactorial/polygenic inheritance with incomplete penetrance and variable expressivity. Classic dominant, recessive, X-linked, mitochondrial inheritance, anticipation, and a single carrier frequency are not generally applicable. Mendelian or chromosomal syndromes form a minority and should be coded separately. Consanguinity may increase risk of rare recessive syndromic NTDs but is not the main mechanism of nonsyndromic MMC. Familial recurrence is higher than population risk and warrants genetic counseling.

Epidemiology

Rates vary substantially by geography, ancestry, ascertainment, prenatal diagnosis/termination, folate policy, and whether stillbirths are counted. A 2024 Swedish registry study of 1,735 people found prevalence declined from 5.2 to 1.2 per 10,000 births between 1973 and 2021. A Brazilian review cited 2.67 per 10,000 births in 2017–2019. A U.S. MOMS follow-up paper described MMC as affecting approximately 1 in 1,500 births, whereas the 2024 Science study noted historical prevalence greater than 1 in 2,500 before fortification. These estimates are not contradictory because definitions, periods, and populations differ. (ferreira2024interventionstoimprove pages 1-3, vong2024riskofmeningomyelocele pages 1-2, houtrow2020prenatalrepairof pages 1-2, andersson2024mortalityratescause pages 1-2)

Female excess is often reported for NTDs, but sex ratios vary and no universal cystica-specific ratio should be assigned without a defined registry. Higher historical rates occur in regions without fortification and in some Hispanic/Latino, Celtic, northern Chinese, South Asian, Middle Eastern, and African populations; social disadvantage and access to prevention, prenatal diagnosis, and surgery strongly influence observed burden.

10. Diagnostics

Prenatal screening and confirmation

• Maternal serum alpha-fetoprotein: elevated with open NTDs, typically assessed around 15–20 weeks; it is a screening marker, not a definitive diagnosis.
• Ultrasound: identifies the spinal defect/sac and cranial signs such as ventriculomegaly, “lemon” and “banana” signs, and hindbrain herniation. One synthesis reported 85–90% accuracy for maternal AFP at 16 weeks or fetal ultrasound at 18–20 weeks, but performance depends on operator and protocol. (mathew2018antenataldiagnosismaternal pages 14-17)
• Fetal MRI: refines lesion level, hindbrain anatomy, ventriculomegaly, associated anomalies, and fetal-surgery planning.
• Amniocentesis/CMA: offered when anomalies or fetal surgery are being considered; karyotype/CMA assess aneuploidy and pathogenic CNVs, including 22q11.2 deletion.

Postnatally, examination defines sac integrity and functional neurological level. Cranial/spinal ultrasound and MRI assess hydrocephalus, Chiari II, cord anatomy and tethering. Renal/bladder ultrasound, serum creatinine interpreted cautiously, catheterization assessment, and urodynamics characterize neurogenic bladder. Orthopedic, developmental, vision/hearing, sleep/respiratory, and skin assessments are individualized. Biopsy is not diagnostic; EEG/EMG are not routine unless indicated.

Genetic testing strategy

For isolated MMC, start with careful dysmorphology/family/exposure history and chromosomal microarray, especially when additional anomalies are present. The 2024 22q11.2 result strengthens the rationale for CNV detection. Karyotype detects large rearrangements but misses many submicroscopic CNVs; FISH is useful for targeted confirmation/family testing but not genome-wide screening. WES/WGS may be considered for syndromic, recurrent, familial, or unexplained cases, preferably as a trio. Panels may include PCP/neurulation genes but have limited validated yield. Mitochondrial and repeat-expansion testing are not routine.

Differential diagnoses include meningocele versus MMC, closed lipomyelomeningocele, myeloschisis, dermal sinus, sacrococcygeal teratoma, spinal hemangioma, caudal regression/sacral agenesis, split-cord malformation, cloacal exstrophy/OEIS, encephalocele, and amniotic-band disruption.

There is no conventional newborn biochemical screen, asymptomatic carrier screen, or validated liquid biopsy for nonsyndromic MMC.

11. Outcome and prognosis

Prognosis depends on lesion level, functional motor level, hydrocephalus/brainstem dysfunction, prematurity, associated anomalies, renal preservation, infection, access to multidisciplinary care, and socioeconomic context. Approximately 85% of people with spina bifida are estimated to survive into adulthood. (andersson2024mortalityratescause pages 1-2)

In a 2021 meta-analysis of 20 population-based studies, encompassing more than 30 million births and about 12,000 affected infants, infant mortality and case-fatality declined over time. Preterm birth carried RR 4.45 and low birthweight RR 4.77 for infant case-fatality. Higher lesion level, hydrocephalus, multiple anomalies and social/demographic factors also increased risk. (ho2021neonatalandinfant pages 13-15, ho2021neonatalandinfant pages 1-2)

A Finnish national cohort of 181 live-born cases found 7.2% early neonatal mortality; prematurity had uOR 6.96, syndromic status uOR 125.67, and maternal age ≥35 years uOR 5.33, although estimates were unadjusted and imprecise. (kancherla2023earlyneonatalmortality pages 1-6)

The 2024 Swedish study found first-year survival improved from 75% to 94%. Childhood deaths were associated mainly with congenital anomalies, hydrocephalus and infection. Adult concerns included infection, kidney failure, bladder malignancy, self-inflicted injury and substance abuse, supporting proactive urological and mental-health surveillance. (andersson2024mortalityratescause pages 1-2)

Recovery of established paralysis is limited. Preservation of ambulation is more likely with lower lesions, better prenatal motor function, absence of severe deformity and selected prenatal repair. Independence and quality of life are modifiable through rehabilitation, assistive technology, bowel/bladder programs, educational support, accessible environments and effective transition care.

12. Treatment and real-world implementation

Repair

For infants without prenatal repair, the lesion is covered with sterile nonadherent dressings, latex exposure is minimized, and closure is generally performed within 24–48 hours to protect tissue and reduce infection risk. Closure does not reverse the primary developmental lesion. (mathew2018antenataldiagnosismaternal pages 14-17)

Selected fetuses with T1–S1 MMC, hindbrain herniation, suitable gestational age and no major contraindication may undergo open or fetoscopic prenatal repair at expert centers. MOMS demonstrated reduced hindbrain herniation/shunt need and improved motor outcomes, balanced against maternal hysterotomy risks and prematurity.

At school age, 161 MOMS children showed no difference in Vineland adaptive behavior (89.0 versus 87.5; P=.35), but prenatal repair yielded better FRESNO motor-function scores (92 versus 85; P<.001), less hindbrain herniation (60% versus 87%), fewer shunts (49% versus 85%), and fewer shunt revisions among shunted children (47% versus 70%). Walking without orthotics/devices was 29% versus 11% (P=.06), and parent-reported quality of life/family impact favored prenatal repair. The authors concluded there was “no strong evidence of improved cognitive functioning.” (houtrow2020prenatalrepairof pages 1-2)

Lifelong complication management

• Hydrocephalus: ventriculoperitoneal shunt or selected endoscopic procedures; urgent evaluation of headache, vomiting, lethargy, cognitive change, swallowing/respiratory symptoms, or neurological decline.
• Bladder: clean intermittent catheterization, antimuscarinic or β3-agonist therapy when appropriate, urodynamic surveillance, antibiotic treatment for symptomatic UTI, botulinum toxin, and reconstructive surgery in selected high-pressure bladders. There is no disease-specific pharmacogenomic algorithm.
• Bowel: timed toileting, fiber/fluid optimization, osmotic or stimulant laxatives, suppositories/enemas, transanal irrigation, or antegrade continence enema.
• Orthopedics/mobility: physical therapy, orthoses, standing/walking programs, wheelchairs, contracture management and indicated orthopedic surgery.
• Skin/bone: daily inspection, pressure relief, nutrition, weight management, vitamin D/bone-health evaluation and fracture prevention.
• Tethered cord: surgery is reserved for concordant progressive neurological, urological, pain, or orthopedic deterioration—not MRI appearance alone.
• Neurodevelopment/participation: neuropsychology, school accommodations, occupational and physical therapy, self-management training, vocational planning, sexual/reproductive health, mental-health care and structured transition to adult services. A 2024 rehabilitation review retained 18 intervention studies and found increased independence with camp-based, CO-OP and occupation-based approaches. (ferreira2024interventionstoimprove pages 1-3)

Suggested NCIt intervention mappings include surgical repair procedure, fetal surgery, neurosurgical procedure, ventriculoperitoneal shunt, physical therapy, occupational therapy, rehabilitation therapy, intermittent urinary catheterization, botulinum toxin therapy, and mesenchymal stromal cell therapy. Exact NCIt identifiers should be validated against the current NCIt release.

Experimental therapy

CuRe, NCT04652908: recruiting Phase 1/2a, estimated n=55; 35 participants receive placental mesenchymal stem cells seeded on extracellular-matrix dural graft during open fetal repair, with 20 contemporaneous untreated controls. Safety at birth is primary; 30-month endpoints include motor level at least two segments better than anatomical expectation, independent walking, bowel function and urodynamics. This is FDA-regulated and investigational, not standard therapy. (NCT04652908 chunk 1, NCT04652908 chunk 2)

Other recent studies include completed NCT04027374 on stress-associated neonatal epigenetic changes after fetal surgery (actual n=70); recruiting NCT06796972 on parental decision-making and psychological impact (estimated n=44); and NCT07048691, a small active observational ultrasound-outcome study (n=20). The latter records were posted in 2025 and should not be represented as 2023–2024 evidence. (NCT04027374 chunk 1, NCT04027374 chunk 2, NCT07048691 chunk 1, NCT06796972 chunk 1)

No approved gene therapy, CRISPR therapy, RNA therapy, or immune-targeted therapy exists for MMC.

13. Prevention

Primary prevention

• Provide 400 µg folic acid daily to all who may become pregnant, beginning before conception and continuing through early pregnancy; use clinician-directed high-dose folate after a prior NTD pregnancy or other high-risk circumstances.
• Implement mandatory staple-food fortification and monitor red-cell folate at population level.
• Optimize diabetes control and preconception weight.
• Review antiseizure and folate-antagonist drugs before pregnancy; do not abruptly stop essential medication. Avoid valproate where an effective safer alternative exists.
• Avoid hyperthermia and correct B12 deficiency.

Fortification has reduced prevalence and may reduce severity. Infants born in the postfortification period were reported as almost one-third less likely to die in infancy than those in the prefortification period, although concurrent improvements in diagnosis and care contribute. (ho2021neonatalandinfant pages 13-15)

Secondary and tertiary prevention

Secondary prevention comprises maternal-serum screening, high-quality prenatal ultrasound, confirmatory MRI/genetic assessment, nondirective counseling and timely referral to fetal/pediatric neurosurgery. Prenatal repair prevents some secondary cord injury but does not prevent the initial malformation.

Tertiary prevention includes prompt closure, hydrocephalus and renal surveillance, catheterization/bowel programs, skin and orthopedic prevention, immunization according to standard schedules, rehabilitation, mental-health care, and transition planning. There is no MMC-specific vaccine or antimicrobial prophylaxis for the general population.

14. Other species and naturally occurring disease

Comparable congenital spinal dysraphism occurs sporadically in domestic animals, including dogs, cats, calves, lambs and foals, but robust breed-level epidemiology and validated VBO mappings are sparse. It is noninfectious and has no zoonotic or cross-species transmission. Veterinary lesions resemble human meningocele/MMC anatomically, but hydrocephalus/Chiari II and long-term multidisciplinary survival are less consistently represented. Species identifiers include human NCBITaxon:9606, mouse 10090, sheep 9940, zebrafish 7955, chicken 9031, dog 9615, and cat 9685.

15. Model organisms and advanced technologies

Mouse

More than 400 mouse genes can produce NTDs, illustrating genetic heterogeneity. Crkl loss is a particularly strong translational model because it functionally validates the human 22q11.2 association and demonstrates folate-modified penetrance. Strengths are mechanistic genetics and controlled diet; limitations include species-specific neurulation, allele effects, and folate exposure. (vong2024riskofmeningomyelocele pages 1-2, aguiarpulido2021systemsbiologyanalysis pages 1-3)

The Grhl2 Axial defects model contains a noncoding LTR insertion causing excess Grhl2 expression and spinal NTDs plus craniofacial defects. It demonstrates that regulatory gain of expression—not only protein loss—can disrupt neurulation. Human upstream variants remain unvalidated. (cranesmith2023anoncodinginsertional pages 1-2)

Other models include curly-tail/Grhl3, loop-tail/Vangl2, Scrib, Celsr1, Shroom3 and folate-antagonist/valproate-induced models. They recapitulate closure failure but not always the human open-lesion secondary injury and Chiari II phenotype.

Sheep and other models

Surgically created fetal sheep MMC models reproduce exposed-cord secondary injury and permit human-scale fetal repair. In-utero closure has produced near-normal motor function, intact sensation and improved bowel/bladder outcomes in preclinical studies. The limitation is that the lesion is induced surgically rather than arising through primary neurulation failure. (mathew2018antenataldiagnosismaternal pages 14-17)

Chick and zebrafish models permit live imaging and pathway manipulation but differ anatomically from human spinal neurulation. Human pluripotent-stem-cell neural tube organoids model neuroepithelial patterning, morphogenesis and toxicant response, but currently do not reproduce the complete vertebral, meningeal, amniotic-fluid, hindbrain and lifelong-organ phenotype.

Evidence interpretation and knowledge gaps

The highest-confidence evidence consists of randomized or longitudinal MOMS outcomes, population registries/meta-analysis, randomized folate-prevention evidence, and the replicated human 22q11.2 association with mouse functional validation. Candidate-gene associations, small ancestry-specific GWAS findings, systems-biology classifiers, epigenetic observations, and stem-cell augmentation remain exploratory.

Important gaps include ancestry-diverse genomic cohorts; standardized lesion-specific phenotype frequencies; validated functional interpretation of noncoding variants; maternal–fetal genotype/exposure models; kidney, pain and mental-health outcomes across adulthood; direct comparison of open versus fetoscopic repair; and long-term safety/efficacy of cell-enhanced fetal surgery. Variant-level allele frequencies and ACMG classifications must be obtained from the current ClinVar/gnomAD record for each exact variant and should not be inferred from gene-level association.

Selected exact source statements

• Vong et al., Science, 3 May 2024: “Exome and genome sequencing of 715 parent-offspring trios identified six patients with chromosomal 22q11.2 deletions, suggesting a 23-fold increased risk compared with the general population.” DOI: https://doi.org/10.1126/science.adl1624. (vong2024riskofmeningomyelocele pages 1-2)
• Houtrow et al., Pediatrics, February 2020: “Long-term benefits of prenatal surgery included improved mobility and independent functioning and fewer surgeries for shunt placement and revision, with no strong evidence of improved cognitive functioning.” DOI: https://doi.org/10.1542/peds.2019-1544. (houtrow2020prenatalrepairof pages 1-2)
• Ho et al., PLOS ONE, 12 May 2021: “Preterm birth … and low birthweight … are the strongest risk factors associated with increased spina bifida infant case fatality.” DOI: https://doi.org/10.1371/journal.pone.0250098. (ho2021neonatalandinfant pages 1-2)
• Rísová et al., published 31 December 2024: “Randomized trials have shown that FA supplementation during preconceptional and periconceptional periods reduces the incidence of NTDs by nearly 80%.” DOI: https://doi.org/10.3390/nu17010126. (risova2024preconceptionalandpericonceptional pages 1-3)

PMID note: The retrieved full texts did not consistently display PMIDs. To avoid false identifiers, DOI and ClinicalTrials.gov URLs are provided where verified; PubMed IDs should be added only after direct NCBI record validation.

References

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3. (tindula2024genome‐wideanalysisof pages 1-3): Gwen Tindula, Biju Issac, Sudipta Kumer Mukherjee, Sheikh Muhammad Ekramullah, D. M. Arman, Joynul Islam, Hafiza Sultana Suchanda, Liang Sun, Shira Rockowitz, David C. Christiani, Benjamin C. Warf, and Maitreyi Mazumdar. Genome‐wide analysis of spina bifida risk variants in a case–control study from bangladesh. Birth Defects Research, Mar 2024. URL: https://doi.org/10.1002/bdr2.2331, doi:10.1002/bdr2.2331. This article has 5 citations and is from a peer-reviewed journal.

4. (aguiarpulido2021systemsbiologyanalysis pages 1-3): Vanessa Aguiar-Pulido, Paul Wolujewicz, Alexander Martinez-Fundichely, Eran Elhaik, Gaurav Thareja, Alice Abdel Aleem, Nader Chalhoub, Tawny Cuykendall, Jamel Al-Zamer, Yunping Lei, Haitham El-Bashir, James M. Musser, Abdulla Al-Kaabi, Gary M. Shaw, Ekta Khurana, Karsten Suhre, Christopher E. Mason, Olivier Elemento, Richard H. Finnell, and M. Elizabeth Ross. Systems biology analysis of human genomes points to key pathways conferring spina bifida risk. Dec 2021. URL: https://doi.org/10.1073/pnas.2106844118, doi:10.1073/pnas.2106844118. This article has 25 citations and is from a highest quality peer-reviewed journal.

5. (houtrow2020prenatalrepairof pages 1-2): Amy J. Houtrow, Elizabeth A. Thom, Jack M. Fletcher, Pamela K. Burrows, N. Scott Adzick, Nina H. Thomas, John W. Brock, Timothy Cooper, Hanmin Lee, Larissa Bilaniuk, Orit A. Glenn, Sumit Pruthi, Cora MacPherson, Diana L. Farmer, Mark P. Johnson, Lori J. Howell, Nalin Gupta, and William O. Walker. Prenatal repair of myelomeningocele and school-age functional outcomes. Feb 2020. URL: https://doi.org/10.1542/peds.2019-1544, doi:10.1542/peds.2019-1544. This article has 185 citations and is from a highest quality peer-reviewed journal.

6. (andersson2024mortalityratescause pages 1-2): Marie Andersson, Lana Hadi, Michaela Dellenmark Blom, Ulla Sillen, Sofia Sjöström, Magdalena Vu Minh Arnell, and Kate Abrahamsson. Mortality rates, cause and risk factors in people with spina bifida, register‐based study over five decades. Acta Paediatrica, 113:1916-1926, May 2024. URL: https://doi.org/10.1111/apa.17275, doi:10.1111/apa.17275. This article has 10 citations and is from a peer-reviewed journal.

7. (ho2021neonatalandinfant pages 1-2): Peter Ho, Maria A. Quigley, Dharamveer Tatwavedi, Carl Britto, and Jennifer J. Kurinczuk. Neonatal and infant mortality associated with spina bifida: a systematic review and meta-analysis. PLoS ONE, 16:e0250098, May 2021. URL: https://doi.org/10.1371/journal.pone.0250098, doi:10.1371/journal.pone.0250098. This article has 52 citations and is from a peer-reviewed journal.

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9. (risova2024preconceptionalandpericonceptional pages 1-3): Vanda Rísová, Rami Saade, Vladimír Jakuš, Lívia Gajdošová, Ivan Varga, and Jozef Záhumenský. Preconceptional and periconceptional folic acid supplementation in the visegrad group countries for the prevention of neural tube defects. Nutrients, 17:126, Dec 2024. URL: https://doi.org/10.3390/nu17010126, doi:10.3390/nu17010126. This article has 17 citations.

10. (ferreira2024interventionstoimprove pages 1-3): Rafaela Fernandes Alvarenga Ferreira and Ana Cristina de Jesus Alves. Interventions to improve independence in basic and instrumental activities of daily living in individuals with myelomeningocele: an integrative literature review. Cadernos Brasileiros de Terapia Ocupacional, Jan 2024. URL: https://doi.org/10.1590/2526-8910.ctoar291837922, doi:10.1590/2526-8910.ctoar291837922. This article has 0 citations.

11. (NCT04652908 chunk 1): Cellular Therapy for In Utero Repair of Myelomeningocele - The CuRe Trial. University of California, Davis. 2021. ClinicalTrials.gov Identifier: NCT04652908

12. (NCT04652908 chunk 2): Cellular Therapy for In Utero Repair of Myelomeningocele - The CuRe Trial. University of California, Davis. 2021. ClinicalTrials.gov Identifier: NCT04652908

13. (NCT04027374 chunk 2): Stress-associated Epigenetic Alterations in Newborns After Fetal Surgery. University Children's Hospital, Zurich. 2019. ClinicalTrials.gov Identifier: NCT04027374

14. (NCT04027374 chunk 1): Stress-associated Epigenetic Alterations in Newborns After Fetal Surgery. University Children's Hospital, Zurich. 2019. ClinicalTrials.gov Identifier: NCT04027374

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16. (mathew2018antenataldiagnosismaternal pages 14-17): ME Mathew. Antenatal diagnosis, maternal and neonatal outcome analysis of myelomeningocele, spina bifida at the lithuanian university of health sciences hospital (2016-2017 …. Unknown journal, 2018.

17. (cranesmith2023anoncodinginsertional pages 1-2): Zoe Crane-Smith, Sandra C P De Castro, Evanthia Nikolopoulou, Paul Wolujewicz, Damian Smedley, Yunping Lei, Emma Mather, Chloe Santos, Mark Hopkinson, Andrew A Pitsillides, Richard H Finnell, M Elisabeth Ross, Andrew J Copp, and Nicholas D E Greene. A non-coding insertional mutation of grhl2 causes gene over-expression and multiple structural anomalies including cleft palate, spina bifida and encephalocele. Human Molecular Genetics, 32:2681-2692, Jun 2023. URL: https://doi.org/10.1093/hmg/ddad094, doi:10.1093/hmg/ddad094. This article has 12 citations and is from a domain leading peer-reviewed journal.

18. (kancherla2023earlyneonatalmortality pages 1-6): Vijaya Kancherla, Sanjida Mowla, Sari Räisänen, and Mika Gissler. Early neonatal mortality among babies born with spina bifida in finland (2000–2014). American Journal of Perinatology, 40:1208-1216, Aug 2023. URL: https://doi.org/10.1055/s-0041-1733957, doi:10.1055/s-0041-1733957. This article has 5 citations and is from a peer-reviewed journal.

19. (NCT07048691 chunk 1): Muhammad Naveed Babur. Prenatal and Postnatal Ultrasonographic Evaluation of Myelomeningocele to Predict Post-Surgical Outcomes. Superior University. 2025. ClinicalTrials.gov Identifier: NCT07048691

20. (NCT06796972 chunk 1): In Utero Surgery for Fetal Myelomeningocele: Decision-making Mechanisms and Psychological Impact of Prenatal Therapy. Assistance Publique - Hôpitaux de Paris. 2024. ClinicalTrials.gov Identifier: NCT06796972

Artifacts

• Edison artifact artifact-00

Reference Validation

Checked with linkml-reference-validator 0.2.1.

References that may not be about this subject

These identifiers resolve, so they are not fabrications, but the records they resolve to share almost none of this report's vocabulary. That is a clue and not a verdict - a paper can be relevant in ways its title and abstract do not spell out - so read them before deciding:

• DOI:10.1542/peds.2019-1544 (8 mentions) - Prenatal Repair of Myelomeningocele and School-age Functional Outcomes
• shared terms: repair, prenatal
• DOI:10.1590/2526-8910.ctoAR291837922 (3 mentions) - Interventions to improve independence in basic and instrumental activities of daily living in individuals with myelomeningocele: an integrative literature review
• shared terms: mmc
• DOI:10.1590/2526-8910.ctoar291837922 (3 mentions) - Interventions to improve independence in basic and instrumental activities of daily living in individuals with myelomeningocele: an integrative literature review
• shared terms: mmc

Weighed against this report's own most characteristic terms: disease, gene, clinical, mmc, genetic, include, human, model, neural, spina, bifida, fetal, variant, primary, repair, risk, folate, open, secondary, prenatal.

All extracted references resolved successfully. Resolving is not the same as being relevant, though - see the references listed above as possibly off topic.