The severe congenital encephalopathy and profound hypotonia were associated with necrotizing myopathy, cardiomyopathy, and cataracts in 3 infants, including 2 sisters (PMID:2317015).
In 2 sisters, offspring of consanguineous parents of Turkish ancestry, and a third unrelated girl born of nonconsanguineous parents, Lyon et al. (1990) described a severe form of congenital encephalopathy and profound hypotonia associated with necrotizing myopathy, cardiomyopathy, ... In 2 sisters, offspring of consanguineous parents of Turkish ancestry, and a third unrelated girl born of nonconsanguineous parents, Lyon et al. (1990) described a severe form of congenital encephalopathy and profound hypotonia associated with necrotizing myopathy, cardiomyopathy, and cataracts. Brain scans suggested agenesis of the corpus callosum; however, neuropathologic examination showed severe atrophy of the corpus callosum, not the usual agenesis, as well as atrophy of the white matter and absence of pyramidal tracts in the medulla. Other findings were considered to be the expression of a primary disorder of axonal development leading to a reduction in interneuronal synaptic contacts. In the Turkish family, the level of parental consanguinity was extraordinarily high. The father of the 2 affected sisters was the product of a brother-sister mating and the mother of the sisters was the daughter of the son of the 'brother' by a presumably unrelated woman. One sister died at 10 months while suffering from varicella; the second died at 16 months from a pulmonary infection.