Partial trisomy 6p and partial monosomy 9p from a de novo translocation 46, XY, ‐9, + DER(9)T(6:9)(p211:p24)

This report describes an adult male with a partial trisomy 6p(p211‐pter) and a partial monosomy 9p(9p24‐pter) resulting from a de novo unbalanced translocation. This patient does not show the classical features of the 9p partial monosomy syndrome, thus disputing the claim of Hoo et al. (1982) that 9p24 is the critical segment for the monosomy syndrome. Partial trisomy for 6p has only been previously reported in children. In addition to the chromosomal anomalies, the patient has autosomal recessive spinal muscular atrophy with a different age of onset than two affected sibs. Finally, he shows unusual audiologic and ophthalmologic signs not previously reported as part of the 9p monosomy or 6p trisomy syndromes.