Partial trisomy of 13(pter to q12) due to 47,XY, + der(13),t(13;22)(q12;q13)mat.

A 36-month-old boy presented with short stature, short neck, shield-shaped chest, and mental retardation. Chromosome analysis showed trisomy for the short arm and the proximal protion of the long arm of chromosome 13 [47,XY, + der(13),t(13;22)(q12;q13)mat]. The patient's mother has a balanced translocation between the long arms of chromosomes 13 and 22 [46,XX,t(13;22)(q12;q13)]. The patient's neutrophils showed an elevated number of nuclear projections and his fetal hemoglobin level was undetectable.