Anophthalmia_Microphthalmia_Coloboma
Gene: MAB21L1
Biallelic variants in MAB21L1 are associated with a syndromic phenotype including ophthalmological presentations such as horizontal nystagmus, bilateral corneal opacities/ corneal dystrophy, strabismus and retinal degeneration. These phenotypes are not relevant for this panel.
However, there is sufficient evidence available for the association of monoallelic MAB21L1 variants with phenotypes relevant to this panel such as microphthalmia and aniridia.Created: 13 May 2026, 4:36 a.m.
PMID:27103078 (2017) reported the identification of a homozygous frameshift variant in MAB21L1 gene (p.Cys246Leufs*18) in a boy with scrotum agensis, ophthalmological anomalies, cerebellar malformation, facial dysmorphism and global developmental delay. Ocular anomalies included nystagmus, convergent strabismus and corneal dystrophy. There is also functional evidence available from knockout mice which presented a similar malformative association of ophthalmological malformations of the anterior chamber and preputial glands hypoplasia.
PMID:30487245 (2019) reported the identification of four homozygous MAB21L1 loss of function variants (p.Glu281fs*20, p.Arg287Glufs*14 p.Tyr280* and p.Ser93Serfs*48) and one missense variant (p.Gln233Pro) in 10 affected individuals from 5 consanguineous families with a distinctive autosomal recessive neurodevelopmental syndrome. Ocular features included horizontal nystagmus, bilateral corneal opacities/ corneal dystrophy, strabismus and retinal degeneration.
PMID:33973683 (2021) reported a heterozygous novel variant in MAB21L1 gene (c.152G>T/ p.Arg51Leu), in two family members with microphthalmia and aniridia, as well as novel or rare compound heterozygous variants of uncertain significance (c.184C>T/ p.Arg62Cys; c.-68T>C and c.658G>C/ p.Gly220Arg; c.*529A>G) in two additional probands with microphthalmia, coloboma and/or cataracts. There is also function evidence available from in vitro studies of coding variants and in vivo complementation assays using the zebrafish mab21l2 Q48Sfs*5 loss-of-function line.
PMID:36413568 (2022) reported nine patients from five families with severe aniridia and/or microphthalmia with ultrarare monoallelic missense variants altering the Arg51 codon of MAB21L1. The detected variants are c.152G>A/ p.Arg51Gln, c.152G>T/ p.Arg51Leu, c.152G>C/ p.Arg51Pro and c.155T>G/ p.Phe52Cys. Mice engineered to carry the p.Arg51Leu change showed a highly-penetrant optic disc anomaly in heterozygous animals with severe microphthalmia in homozygotes.
PMID:36446583 (2023) reported the identification of a novel missense variant (p.Phe52Leu) in a three-generation pedigree with autosomal dominant microphthalmia.
PMID:36892533 (2023) reported the identification of three heterozygous missense variants in MAB21L1 gene in five unrelated families, including c.152G>T/ p.Arg51Leu in two, c.152G>A/ p.Arg51Gln in two, and c.155T>G/ p.Phe52Cys in one. All patients presented with similar blepharophimosis plus anterior segment and macular dysgenesis (BAMD) phenotype.
PMID:39016008 (2024) reported an additional family with four individuals diagnosed with microphthalmia and with Arg51 variant in MAB21L1 gene.
Only biallelic variants in this gene are associated with relevant phenotypes in OMIM (MIM #618479, last accessed 12 May 2026), Gene2Phenotype (with 'definitive' rating on the DD and Eye panels) and ClinGen (Strong rating by Syndromic disorders Expert panel - https://search.clinicalgenome.org/CCID:008388) However, only monoallelic variants are associated with phenotypes relevant to this panel.Created: 13 May 2026, 4:35 a.m.
Mode of inheritance
MONOALLELIC, autosomal or pseudoautosomal, NOT imprinted
Publications
Sources: LiteratureCreated: 29 Jan 2020, 1:01 p.m.
Mode of inheritance
BIALLELIC, autosomal or pseudoautosomal
Phenotypes
Cerebellar, ocular, craniofacial, and genital syndrome OMIM#618479
Publications
Phenotypes for gene: MAB21L1 were changed from Cerebellar, ocular, craniofacial, and genital syndrome OMIM#618479 to Cerebellar, ocular, craniofacial, and genital syndrome OMIM#618479; Microphthalmia MONDO:0021129, MAB21L1-related
Publications for gene: MAB21L1 were set to 30487245
Mode of inheritance for gene: MAB21L1 was changed from BIALLELIC, autosomal or pseudoautosomal to BOTH monoallelic and biallelic, autosomal or pseudoautosomal
Gene: mab21l1 has been classified as Green List (High Evidence).
Gene: mab21l1 has been classified as Green List (High Evidence).
gene: MAB21L1 was added gene: MAB21L1 was added to Anophthalmia_Microphthalmia_Coloboma. Sources: Literature Mode of inheritance for gene: MAB21L1 was set to BIALLELIC, autosomal or pseudoautosomal Publications for gene: MAB21L1 were set to 30487245 Phenotypes for gene: MAB21L1 were set to Cerebellar, ocular, craniofacial, and genital syndrome OMIM#618479 Penetrance for gene: MAB21L1 were set to Complete Review for gene: MAB21L1 was set to GREEN