Ectodermal Dysplasia, Hypohidrotic, With Hypothyroidism And Agenesis Of The Corpus Callosum

Among the children of healthy nonconsanguineous parents, Fryns et al. (1989) described a boy with severe mental retardation, hypohidrotic ectodermal dysplasia, primary hypothyroidism, and agenesis of the corpus callosum. A thyroid scintigram with technetium 99 showed absence of normal thyroid gland tissue and the presence of an ectopic goiter at the base of the tongue. Low T3 and T4 and elevated TSH confirmed the clinical suspicion of hypothyroidism and demonstrated its primary nature. Soekarman and Fryns (1993) described an 8-year-old boy who presumably had the same disorder. The boy was born with a Pierre Robin sequence, and feeding problems were present from birth. He had recurrent respiratory tract and eye infections. He was severely mentally retarded and had cerebellar hypoplasia. A specific facies included frontal bossing, hypoplasia of the maxilla, hypertelorism, protruding tongue, low-set ears, and tooth anomalies. The patient reported by Fryns et al. (1989) had a similar facial appearance, swallowing difficulties, and frequent respiratory tract and eye infections. He too had enlarged lateral ventricles on his CT scan. Devriendt et al. (1996) reported a similarly affected 3-year-old hypotonic boy with severe mental retardation, macrocephaly, agenesis of the corpus callosum, small cerebellum, ptosis of the eyelids, low set ears, retrognathia, microdontia with enamel defects, pectus excavatum, supernumerary nipples, long slender fingers, and hypoplastic scrotum. His mother was mildly mentally retarded and had macrocephaly, midface hypoplasia, retrognathia, and long slender fingers, but no evidence of ectodermal dysplasia.

This disorder and that discussed in 225050 may be X-linked and may represent a contiguous gene syndrome.