Microphthalmia, syndromic 1

Syndromic microphthalmia-1 (MCOPS1) is an X-linked disorder characterized by unilateral or bilateral microphthalmia or anophthalmia. The most common extraocular features are impaired intellectual development, large and dysplastic ears with skin tags, high-arched or cleft palate, dental anomalies, urogenital anomalies, and skeletal manifestations including lordosis or scoliosis, clinodactyly, syndactyly, brachydactyly, and abnormal thumbs. There is considerable variation in severity among reported families (Slavotinek et al., 2005). Genetic Heterogeneity Other forms of syndromic microphthalmia include MCOPS2 (300166), caused by the BCOR gene (300485) on chromosome Xp11; MCOPS3 (206900), caused by mutation in the SOX2 gene (184429) on chromosome 3q26; MCOPS5 (610125), caused by mutation in the OTX2 gene (600037) on chromosome 14q22; MCOPS6 (607932), caused by mutation in the BMP4 gene (112262) on chromosome 14q22; MCOPS7 (309801), caused by mutation in the HCCS gene (300056) on chromosome Xp22; MCOPS9 (601186), caused by mutation in the STRA6 gene (610745) on chromosome 15q24; MCOPS11 (614402), caused by mutation in the VAX1 gene (604294) on chromosome 10q25; MCOPS12 (615524), caused by mutation in the RARB gene (180220) on chromosome 3p24; MCOPS13 (300915), caused by mutation in the HMGB3 gene (300193) on chromosome Xq28; MCOPS14 (615877), caused by mutation in the MAB21L2 gene (604357) on chromosome 4q31; and MCOPS15 (615145), caused by mutation in the TENM3 gene (610083) on chromosome 4q. A form of syndromic microphthalmia also maps to chromosome 6q21 (MCOPS8; 601349). A form of microphthalmia associated with progressive brain atrophy has been reported (MCOPS10; 611222). A form of syndromic microphthalmia, formerly designated MCOPS4, has been found to be the same entity as MCOPS1. Williamson and FitzPatrick (2014) reviewed genes associated with microphthalmia, anophthalmia, and/or coloboma phenotypes. They noted that when exon sequencing is combined with detection of gene deletions via aCGH and high-resolution analysis of intragenic microdeletions and microduplications, approximately 75% of cases of bilateral anophthalmia or severe microphthalmia are found to carry heterozygous mutations in the SOX2 (184429) or OTX2 (600037) genes, or biallelic mutations in the STRA6 gene (610745) (see also MCOPS5, 610125 and MCOPS9, 601186).

OMIM