Ataxia-Microcephaly-Cataract Syndrome

In a highly inbred Arab family with ataxia-telangiectasia of complementation group A (ATA; 208900), Ziv et al. (1992) found 3 individuals who had ataxia, hypotonia, microcephaly, and congenital cataracts with nystagmus. Mental retardation was also observed in 1 of the 3 persons. The one individual appeared to be affected with both ataxia-telangiectasia and the AMC syndrome. Findings of the AMC syndrome resembled the Marinesco-Sjogren syndrome (MSS; 248800); however, microcephaly is not part of MSS, and mental retardation was present in only 1 of the AMC patients. Cataract is not characteristic of any of the known disorders that simulate ataxia-telangiectasia. That the AMC syndrome was an entity separate from AT in the Arab family was indicated by linkage studies.