DENOVO PARTIAL MONOSOMY 21 WITH UNUSUAL KARYOTYPE

A fifteen month old girl with multiple congenital anomalies, mental retardation and de novo partial monosomy 21 with unusual karyotype is described. Anomalies are hypertonia, scaphocephaly, prominent occiput, hypertelorism, telecanthus, antimongoloid slanting of the eyes, absent philtrum pillars, characteristic long tapering spindle shaped fingers with adducted thumbs crossing the palm. High resolution banding showed mosaic two cell lines each with a modal number of 45 chromosomes, but carrying different translocations finally resulting in partial monosomy for the segment 21pter .fwdarw. q21.2.