Two chromosomal syndromes in the same family: monosomy and trisomy for part of the short arm of chromosome 10.

A grandfather with balanced translocation t(1:10) gave rise to three possible combinations involving chromosome 10: balanced translocation and trisomy for part of the short arm 10p13 leads to pter in the second generation, and mono- and trisomy 10p13 leads to pter in the third generation. The clinical signs and symptoms of the present case with monosomy 10p13 leads to pter are compared with those of 9 earlier reported cases with a deleted 10p. Together they represent a clinically recognizable syndrome with antimongoloid eye slant, ptosis, epicanthus, high arched or cleft palate, flat nasal bridge, micrognathia, small round and low-set ears, wide spaced nipples, cardiac and urinary tract abnormalities, hand and foot anomalies, hypoplasia/absence of the olfactory bulbs/tracts, psychomotor and growth retardation. More than 20 cases of the trisomy 10p syndrome have been described earlier. The most constant clinical findings are mental retardation, dolichocephaly, frontal bossing, broad nasal bridge, cheilo-palatoschisis, retrognathia and variable internal malformations. We found, however, the clinical characteristics in this syndrome more variable than for the monosomy 10p13 leads to pter syndrome. Our two cases, representing the eldest and the youngest described, have rather few of the typical characteristics, and few in common with each other. This indicates the difficulty in making this diagnosis on clinical features only without a cytogenetic verification.