A de novo case of trisomy 10p: gene dosage studies of hexokinase, inorganic pyrophosphatase and adenosine kinase.

A female infant with multiple congenital anomalies is presented. Cytogenetic study revealed the presence of a de novo, supernumerary, small telocentric chromosome exhibiting the banding pattern of the short arm of chromosome no. 10 [47,XX,+10p(pter----cen)]. Her clinical features were compatible with the 10p trisomy syndrome. Hexokinase (HK-1) activity was elevated in the patient's erythrocytes, which is consistent with an assignment of HK-1 to 10pter---cen10. The absence of a gene dosage effect for inorganic pyrophosphatase (PP) in this study indicates exclusion of PP from 10pter ----cen10, and therefore implies a regional assignment of cen10----10q24 for PP. Adenosine kinase (ADK) activity was within control limits, which is consistent with exclusion of ADK from 10pter----cen10.