Inversion-duplication of bands q13----q21 of human chromosome 9.
Structural abnormalities involving heterochromatic regions of the human genome are difficult to characterize because these segments are G-band negative by GTG technique, a routinely used procedure in clinical cytogenetic laboratories. Chromosome abnormalities of such cases have gone undetected or were incorrectly characterized because these regions are so-called heteromorphisms or variants. Consequently, much anxiety has been aroused by the confusion between a chromosome abnormality and a normal heteromorphic variant. We report the first documented case with a so-called highly unusual h region of chromosome 9 which is not a variation but a structural rearrangement involving a paracentric inversion and a duplication. The major clinical features were psychomotor retardation, microcephaly, narrow palpebral fissures, renal and genital anomalies, vertebral anomalies, protruding tongue, and learning and behavioral problems. A concise review of variable duplicated segments of 9q is also provided.
Luke
S
S
Long Island College Hospital, Brooklyn, New York 11201.
Verma
R S
RS
PeBenito
R
R
Macera
M J
MJ
D000015:Abnormalities, Multiple / Q000235:genetics*; D000293:Adolescent; D002871:Chromosome Banding; D007446:Chromosome Inversion; D002899:Chromosomes, Human, Pair 9; D005260:Female; D006801:Humans; D008607:Intellectual Disability / Q000235:genetics; D007621:Karyotyping; D001523:Mental Disorders / Q000235:genetics; D014314:Trisomy