Split-Hand With Congenital Nystagmus, Fundal Changes, And Cataracts

In a father and daughter with split-hand/split-foot deformity, Karsch (1936) found horizontal undulatory nystagmus, squint, fundal changes and cataract, which in the father appeared at a late age and in the daughter appeared earlier. Neugebauer (1962) described affected half sibs, a brother and sister aged 7 months and 42 months, respectively. The mother of the 2 children (by different husbands) was normal. Cataract was not present. Pilarski et al. (1985) reported this syndrome in a mother and 3 of her children. The mother showed in the hands the unusual articulating 'crossbone' seen in other cases of classic split-foot/split-hand. In this patient the abnormality was bilaterally symmetrical in the hands, which were monodactylous.

Wong et al. (1998) reported on 2 sisters with Karsch-Neugebauer syndrome (KNS) comprising split foot and split hand anomalies in association with congenital nystagmus. The sisters shared a nearly identical phenotype with the 8 previously reported cases. Although genetic heterogeneity could not be formally excluded, most evidence suggested autosomal dominant inheritance for KNS. If this is the case, the report of 2 affected sibs born to healthy parents is the second instance of apparent gonadal mosaicism; Neugebauer (1962) described an affected male and female with the same unaffected mother but different fathers. Wong et al. (1998) gave a follow-up on the family reported by Pilarski et al. (1985). An affected male in that family had fathered an affected boy, the first incidence of male-to-male transmission.