G syndrome: An unusual family

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Abstract
The G syndrome is a multiple congenital anomaly (MCA) syndrome of hypertelorism., hypospadias, stridor, and swallowing difficulties. Cleft lip and palate, cardiac defects, cranial asymmetry, and bowel obstruction are occasional manifestations. Family data suggest autosomal dominant inheritance. Males appear to have more serious manifestations, whereas most females with the G syndrome have a benign course and are ascertained through affected male relatives. In the family reported here, the proposita was first seen at age 7 weeks because of swallowing difficulties., stridor, and unusual facial appearance, reminiscent of the G syndrome. Evaluation of the family showed striking facial changes in her father and all four of his sibs. These five individuals had megalencephaly, hypertelorism., and a broad prominent nasal root and bridge, reminiscent of the facial appearance in the BBB syndrome. There was no evidence for dysphagia, respiratory abnormality, or hoarse voice in any other relative. These individuals with the G syndrome display two unusual manifestations. There are no males with hypospadias; the proposita has the most severe laryngotracheoesophageal symptoms. Although hypospadias is not an invariable manifestation of the G syndrome and although six females with severe dysphagia or respiratory abnormalities have been reported previously, the manifestations in this family underline the variability of this condition and provide further support that the G syndrome can be expressed with equal severity in both males and females. Although phenotypic overlap between the BBB and G syndromes has long been recognized, many still consider them to be distinct nosologic entities. The occurrence of both BBB and G syndrome in different members of the same family has been observed previously. In this family the characteristic phenotype of the G syndrome in our proposita, coupled with traits in keeping with the BBB syndrome in her father and his sibs, adds credence to the contention that the G and the BBB syndromes are but different expressions of the same mutant gene.