engleski

Two sibs with sensorineural deafness and apparently mild variant of Roberts syndrome

Roberts syndrome (RS) is a rare autosomal recessive disorder characterized by symmetric limb defects, craniofacial abnormalities including cleft lip/palate, somatic and developmental delay, and a variety of other less common abnormalities. Limb defects vary from the complete tetraphocomelia to mild growth deficiency. There are very few reports on mild clinical presentation, but even mild cases exhibit at least minor limb involvement. Chromosomes of RS patients often show characteristic cytogenetic phenomenon called RS effect, premature centromere separation (PCS) or heterochromatin repulsion, consisting of puffing or splitting apart of the constutive heterochromatin around the centromeres, and splaying of the acrocentrics and distal Yq. Here we present the results of the cytogenetic and clinical investigation in two sibs, brother and sister, with typical RS phenomenon in their cells, brother having additionally 47, XYY karyotype. The clinical presentation in both sibs is highly atypical. Although they both have prenatal and postnatal growth retardation, microcephaly, and mild developmental delay, no limb involvement, no dysmorphic features, and no abnormalities described in RS patients are observed, including hypoplastic nasal alae and hemangiomata considered to be specifically associated with mild cases of RS. On the other hand, they have a severe sensorineural hearing impairment which has not been described in RS patients. Cytogenetic analysis from both healthy parents revealed normal karyotype with no evidence of PCS. We conclude that our patients present either an unusually mild form of RS or a new syndrome with RS effect consisting of severe sensorineural deafness, growth retardation and mild developmental delay.

premature centromere separation; Roberts syndrome; sensorineural deafness; microcephaly

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