Diamond-Blackfan Anemia 15 with Mandibulofacial Dysostosis: A Comprehensive Disease Characteristics Report

Diamond-Blackfan anemia 15 with mandibulofacial dysostosis (DBA15) is an ultra-rare ribosomopathy defined by the coexistence of classic Diamond-Blackfan anemia (DBA)—a congenital, typically macrocytic pure red cell aplasia—and a characteristic pattern of craniofacial malformation within the mandibulofacial dysostosis (MFD) spectrum, caused by heterozygous germline mutation of the ribosomal protein gene RPS28 on chromosome 19p13.2.[1][4][8] It represents a genetically and clinically distinct subtype within the broader DBA syndrome, which encompasses multiple ribosomal protein and related genes, yet it shares the core pathophysiological mechanism of impaired ribosome biogenesis leading to nucleolar stress, p53 activation, and selective apoptosis of erythroid progenitors and craniofacial neural crest derivatives.[2][11][13][20] De novo loss-of-function variants that specifically disrupt the canonical translation initiation codon of RPS28 have been identified in at least two unrelated probands with DBA and Treacher Collins–like MFD features, firmly establishing RPS28 haploinsufficiency as the molecular basis of DBA15.[1][2][5][14] The phenotype combines severe early-onset anemia, often manifesting in infancy, with micrognathia, downslanting palpebral fissures, submucous cleft palate or bifid uvula, and malar hypoplasia, alongside variable growth restriction and other congenital anomalies typical of DBA.[2][4][8][11] This report synthesizes current knowledge on DBA15 across epidemiology, genetics, pathophysiology, clinical presentation, diagnostics, prognosis, treatment, prevention, and model systems, integrating evidence from human clinical studies, model organisms, and in vitro functional work to support ontological and mechanistic annotations for a structured disease knowledge base.

1. Disease Information

1.1 Definition and Clinical Overview

Diamond-Blackfan anemia 15 with mandibulofacial dysostosis (DBA15) is formally defined as a subtype of Diamond-Blackfan anemia characterized by the coexistence of DBA and craniofacial anomalies in the MFD spectrum, with a material basis in heterozygous mutation of the RPS28 gene on chromosome 19p13.2.[1][4][8][10] MedGen and Disease Ontology entries describe DBA15 as “Diamond-Blackfan anemia and mandibulofacial dysostosis (micrognathia, downslanting palpebral fissures, submucosal cleft palate or bifid uvula, and malar hypoplasia) that has material basis in heterozygous mutation in the RPS28 gene on chromosome 19p13.2.”[4][8][10] Clinically, the hematological component corresponds to classic DBA syndrome, which is characterized by profound normochromic, usually macrocytic anemia, reticulocytopenia, and severe reduction or absence of erythroid precursors in an otherwise cellular bone marrow, typically presenting in the first year of life.[11][12][13] The craniofacial component overlaps with Treacher Collins syndrome (TCS) and other mandibulofacial dysostoses, with micrognathia, malar hypoplasia, downslanting palpebral fissures, and cleft palate or submucous cleft often noted in affected individuals.[2][5][9][14]

GeneReviews and Orphanet both emphasize that DBA as a syndrome encompasses a spectrum ranging from severe fetal anemia with nonimmune hydrops fetalis to mild or even subclinical erythroid abnormalities with isolated congenital malformations.[4][11][15] DBA15 lies within this spectrum but is distinguished by its specific molecular cause and the consistent presence of MFD features, placing it at the intersection of ribosomopathies that primarily affect hematopoiesis and those that primarily affect craniofacial development.[2][5][13][20] The condition is rare enough that current knowledge is derived almost entirely from aggregated disease-level resources (e.g., OMIM, GeneReviews, MedGen, Orphanet) and a small number of case reports and exome studies rather than large clinical series or registry-based analyses.[1][2][4][5][14]

1.2 Key Identifiers and Ontology Mapping

DBA15 is indexed in several major biomedical databases and ontologies. OMIM lists it under entry #606164 – Diamond-Blackfan anemia 15 with mandibulofacial dysostosis, specifying the causal gene RPS28 (MIM 603685).[1] MedGen assigns Concept ID C4225411 for DBA15, and links it to OMIM 606164 and to the Monarch Initiative disease ontology concept MONDO:0011639.[4] Disease Ontology, via the Zebrafish Model Organism Database (ZFIN) and DOID registry, records DBA15 under DOID:0111894, explicitly defining it as a Diamond-Blackfan anemia with mandibulofacial dysostosis due to heterozygous RPS28 mutation.[8][10] Orphanet includes DBA15 in its broader Diamond-Blackfan anemia entry, which lists multiple OMIM-linked genetic subtypes, including 606164 for RPS28-associated disease.[15]

Standard coding systems for anemia and bone marrow failure syndromes, such as ICD-10 and ICD-11, do not yet distinguish DBA15 from other DBA subtypes but classify DBA under congenital pure red cell aplasia or congenital aregenerative anemia (ICD-10 D61.0, ICD-11 3A60.1).[12][15] MeSH includes “Diamond-Blackfan Anemia” (D029503) but does not yet provide a separate descriptor for DBA15.[15] In the Human Phenotype Ontology (HPO), relevant disease-level mappings include “Diamond-Blackfan anemia” (HP:0001931) and “Mandibulofacial dysostosis” (HP:0001999), which together capture many of the key phenotypic hallmarks of DBA15.[2][5][11] For disease ontology annotation, the primary term is MONDO:0011639 – Diamond-Blackfan anemia 15 with mandibulofacial dysostosis, linked to RPS28 and OMIM 606164.[4][8]

1.3 Synonyms and Alternative Names

Several synonymous labels appear across databases and the clinical literature. MedGen and NORD list the following synonyms: “DBA15,” “Diamond Blackfan anemia 15 with mandibulofacial dysostosis,” “Diamond Blackfan anaemia 15 with mandibulofacial dysostosis,” “Diamond-Blackfan anemia caused by mutation in RPS28,” and “RPS28 Diamond-Blackfan anemia.”[4][6] OMIM uses “Diamond-Blackfan anemia 15 with mandibulofacial dysostosis; DBA15” to emphasize both the ordinal numbering (15) within the DBA locus series and the distinctive craniofacial phenotype.[1] In research articles, the phenotype is frequently described as “Diamond-Blackfan anemia with mandibulofacial dystostosis” or as a “Treacher Collins–like phenotype with DBA,” reflecting the observed overlap with TCS.[2][5][14]

These synonyms reflect the evolution of nomenclature from purely phenotypic descriptions (DBA with MFD, DBA-TCS overlap) to more precise genotype-driven labels specifying the causal gene (RPS28), consistent with modern practice in monogenic disease classification.[2][5][11][14] For ontology alignment, “DBA15” functions as a short-form label, whereas “Diamond-Blackfan anemia 15 with mandibulofacial dysostosis” remains the preferred full name in MONDO and Disease Ontology.[4][8][10]

1.4 Source of Information: Patient-Level vs Aggregated Data

Given the extreme rarity of DBA15, nearly all available information is derived from aggregated disease-level resources based on small numbers of individual patients rather than from large population-based or electronic health record (EHR) datasets.[1][2][4][5][11][14] The foundational evidence for DBA15 comes from the exome sequencing study by Gripp et al. (2014, American Journal of Medical Genetics A), which identified de novo RPS28 start codon mutations in two unrelated probands with DBA and MFD, and from the subsequent OMIM and GeneReviews entries that synthesized these findings into a recognized clinical entity.[1][2][5][11][14] As that study notes, “De novo mutations affecting the RPS28 start codon were found in two unrelated probands, identifying RPS28 as a novel disease gene,” and “We conclude that the phenotype combining features of TCS with DBA is genetically heterogeneous.”[2][5][14]

Broader epidemiologic, diagnostic, and therapeutic data come from large DBA cohorts such as the North American Diamond Blackfan Anemia Registry (DBAR) and other registry-based series, which typically do not distinguish RPS28-associated cases but provide a framework for extrapolating expected hematologic and long-term outcomes.[11][13][18][20] Thus, this report integrates high-resolution genotype–phenotype information from a handful of documented DBA15 cases with generalizable data from DBA registries and reviews, acknowledging that some inferences about incidence, prognosis, and treatment course are extrapolated from the larger DBA population rather than directly demonstrated for DBA15.[11][13][18][20]

2. Etiology

2.1 Primary Disease Causal Factors: Genetic Basis

DBA15 is a monogenic,

Reference Validation

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All extracted references resolved successfully.

Term Validation

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Terms the report names something else

These identifiers resolve, so nothing about them looks wrong, and the ontology calls them something unrelated to what the report calls them. That usually means the identifier is not the one the sentence needs:

• HP:0001931 (1 mention) - the report calls it "Diamond-Blackfan anemia"; HP calls it Hypochromic anemia

Terms whose name is worth a second look

The report's name for these is recognisably related to the term's own name without being one of them. A loose paraphrase reads the same way as a citation of the wrong sibling term - and so does a related synonym, which the ontology records precisely because it names something adjacent rather than the same thing - so these are listed rather than judged:

• MONDO:0011639 (2 mentions) - the report calls it "Diamond-Blackfan anemia 15 with mandibulofacial dysostosis, linked to RPS28 and OMIM 606164"; MONDO calls it Diamond-Blackfan anemia 15 with mandibulofacial dysostosis**
• HP:0001999 (1 mention) - the report calls it "Mandibulofacial dysostosis"; HP calls it Abnormal facial shape, and lists "Facial dysmorphism" among its other names