Familial marker in a Down Syndrome Child.

ABSTRACT

Four months old, female child, referred for cytogenetic analysis, showed mosaiciam for the marker chromosome. Her karyotype 47,XX,+21/48,XX+21 mar (pat). The karyotype of her mother & her sib were normal. Her father showed, similar to the proband, mosaicism for the marker ie 46,XY/47,XY, + mar. AgNOR technique determined the marker as fused short arms of the acrocentric chromosome. Four months old, female child, referred for cytogenetic analysis, showed mosaiciam for the marker chromosome. Her karyotype 47,XX,+21/48,XX+21 mar (pat). The karyotype of her mother & her sib were normal. Her father showed, similar to the proband, mosaicism for the marker ie 46,XY/47,XY, + mar. AgNOR technique determined the marker as fused short arms of the acrocentric chromosome.