Interstitial deletion 13q31 associated with normal phenotype: cytogenetic study of a family with concomitant segregation of reciprocal translocation and interstitial deletion.
Gain or loss of a fragment in human chromosomes has been associated with abnormal phenotypes in numerous genetic disorders. However, it is also possible that lack or excess of a particular chromosomal segment is a neutral polymorphism among populations and thus does not cause obvious abnormal phenotype. In this study, conventional GTG-banded karyotyping and molecular cytogenetic analyses (including fluorescence in situ hybridization, spectral karyotyping and comparative genomic hybridization) were applied to study the genotype-phenotype correlation in a Taiwanese family, in which a concomitant segregation of del(13)(q31q31) interstitial deletion and t(13;18)(q32;p11.2) reciprocal translocation in a 2-year-old girl (the proband) was noticed. Two family members (the father and grandmother of the proband) who carried the del(13)(q31q31) but not the translocation t(13;18) both revealed a normal phenotype at adulthood. The finding, which appears novel, that interstitial deletion 13q31 could be associated with a normal phenotype, is therefore valuable in genetic counseling.
Center for Medical Genetics, Department of Pediatrics, Changhua Christian Hospital, Institute of Medical Research, Chang-Jung Christian University, Changhua, Taiwan.
Yu-Yuan
YY
Ke
Dong-Jay
DJ
Lee
Gwo-Chin
GC
Ma
Mei-Hui
MH
Lee
Bao-Tyan
BT
Wang
Ming
M
Chen
D000015:Abnormalities, Multiple / Q000235:genetics*; D002675:Child, Preschool; D002872:Chromosome Deletion; D002901:Chromosomes, Human, 13-15 / Q000235:genetics*; D005260:Female; D006801:Humans; D008297:Male; D010641:Phenotype; D014178:Translocation, Genetic