Clinical description of a patient carrying the smallest reported deletion involving 10p14 region.

ABSTRACT

Haploinsufficiency of a region located distal to 10p14 designated HDR1, is responsible for hypoparathyroidism, sensorineural deafness, and renal anomalies (HDR syndrome). Haploinsufficiency of a more proximal region, located on 10p13-10p14, designated as DGCR2 is associated with congenital heart defects and thymus hypoplasia/aplasia or T cell defect. We describe a patient showing facial dysmorphisms, delayed psychomotor development and bilateral sensorineural hearing loss and carrying a 10p14 deletion, the smallest deletion found in the literature so far. Our patient, carrying a partial deletion of the DGCR2 region and of the HDR1 region, including the GATA3 gene, showed, unexpectedly, only few of the clinical features of DiGeorge 2 syndrome (psychomotor retardation, palpebral ptosis, epicanthic folds, anteverted nares, cryptorchidism, hand/foot abnormalities) and did not show other typical signs, such as cardiac defect, cleft palate, and abnormal T cell levels. Of the three characteristic features of the HDR syndrome, our patient had only sensorineural deafness. On the basis of the revision of the other cases reported in the literature with a deletion including the 10p14 region, we suggest that GATA3 haploinsufficiency, although not recorded for each patient, is responsible for deafness. The present case shows that even this small 10p deletion is responsible for a specific phenotype. We also underline the importance of CGH-array, in order to obtain a more precise physical mapping of the 10p deletions and an accurate genotype-phenotype correlation.