Studies of malformation syndromes of humans XXXIIIC: The FG syndrome — further studies on three affected individuals from the FG family

Abstract

The brain findings at autopsy of an 18-year-old male with FG syndrome were megalencephaly, midline fusion of mammillary bodies, heterotopia of neuroglial tissue in the 7th and 8th nerves, and ependymal cell replacement by neuroglial tissue as well as a diffuse defect of neuronal cell migration evidenced from pachygyria of many gyri, dysgenesis of cerebral cortex, and heterotopia of neurons in the white matter of the centrum ovale. A cousin, studied at 20 weeks' gestational age, had gross turridolichocephaly with enlarged cranium and also multiple minor external and internal anomalies. An affected brother of this fetus died at 17 months of complications of a congenital heart defect and CNS dysfunction. X-linked inheritance of the FG syndrome is confirmed.

Clinical and behavioral characteristics in FG syndrome

“…Partial agenesis of the corpus callosum was noted in at least one of the initial cases, and in recent years, partial agenesis of the corpus callosum has been reported in a number of cases [Richieri-Costa, 1986;Opitz et al, 1988;Kato et al, 1994;Sorge et al, 1996]. Opitz et al [1982] suggested that the diagnosis of FG syndrome be considered in boys with congenital hypotonia and anorectal anomalies, and in older males with mental retardation, congenital hypotonic joint contractures, chronic constipation, and characteristic facial appearance and personality. Constipation, with or without anal anomalies, is a distinctive major finding of FG syndrome, and it may not resolve until middle childhood for many patients [Romano et al, 1994].…”

Esophageal dysmotility in brothers with an FG-like syndrome

“…There was suggestion of phenotypic overlap with the fragile X syndrome [Loesch et al, 1992;Puissan et al, 1996]. Important manifestations include relative macrocephaly, broad forehead [Opitz and Kaveggia, 1974], anterior cowlick, sparse hair [Thompson et al, 1985], epicanthic folds, dystopia canthorum, hypertelorism, altered ear shape, occasional sensorineural hearing loss [Bianchi, 1984;Neri et al, 1984;Opitz et al, 1982], long philtrum Thompson et al, 1985Thompson et al, , 1987, oral hypotonia with dental malocclusion, and dysarthria [Burn and Martin, 1983]. Other features include square broad hands, broad thumbs, prominent fingertip pads, and high whorl counts [Thompson and Baraitser, 1987].…”

“…Other features include square broad hands, broad thumbs, prominent fingertip pads, and high whorl counts [Thompson and Baraitser, 1987]. Hypotonia may be associated with joint contractures, flat feet, and gena recurvata [Opitz et al, 1982].…”

“…There may be EEG abnormalities with or without seizures [Opitz et al, 1982;Riccardi et al, 1977], and agenesis or thinning of the corpus callosum [Blanco and Boehme, 1986;Opitz and Kaveggia, 1974;Thompson et al, 1985Thompson et al, , 1986. Increased susceptibility to upper respiratory infections in many boys is linked to high infant mortality [Sorge et al, 1996;Thompson and Baraitser, 1987].…”

“…Patients exhibit mild to moderate mental retardation, often with hyperactivity [Opitz et al, 1982] and specific language deficits [McArdle and Wilson, 1993;Romano et al, 1994;Wilson et al, 1987]. There may be EEG abnormalities with or without seizures [Opitz et al, 1982;Riccardi et al, 1977], and agenesis or thinning of the corpus callosum [Blanco and Boehme, 1986;Opitz and Kaveggia, 1974;Thompson et al, 1985Thompson et al, , 1986.…”