Klinefelter variant mosaic with a reciprocal translocation t(1;7).

OBJECTIVE

To determine the constitutional karyotype in a provisional diagnosis of Klinefelter syndrome.

DESIGN

Case report.

SETTING

University research facility in collaboration with a government hospital.

PATIENT(S): Male patient with provisional diagnosis of Klinefelter syndrome.

INTERVENTION(S): Chromosomal analysis of phytohemagglutinin-stimulated peripheral blood lymphocytes using conventional cytogenetic techniques.

MAIN OUTCOME MEASURE(S): Chromosome number and structure, hormonal profile.

RESULT(S): Analysis of GTG-banded metaphases of the proband revealed the karyotype to be mos 48,XXXY,t(1;7)(q42;q32)pat[71%]/47,XXY,t(1;7)(q42;q32)pat[29%]. This is the first report of its kind, to the best of our knowledge. His father and elder brother were also found to be carriers of the same translocation with the karyotype 46,XY,t(1;7)(q42;q32).

CONCLUSION(S): An alternate segregation of the translocation t(1;7) in spermatogenesis could have led to meiotic nondisjunction, thus supporting the hypothesis of interchromosomal effect. This case study truly emphasizes the clinical relevance of cytogenetic diagnosis in the better management of genetic disorders.