47,XXX chromosome constitution in a male

47,XXX male: A clinical and molecular study

We report a 53-year-old Japanese male with a 47,XXX karyotype. His clinical features included hypoplastic scrotal testes (4 ml bilaterally), normally formed small penis (3.8 cm), relatively poor pubic hair development (Tanner stage 3), gynecomastia, age-appropriate male height (159.1 cm), and mental retardation (verbal IQ of 56). Serum testosterone was markedly reduced (0.6 nmol/L). A needle biopsy showed severe testicular degeneration. FISH analysis revealed complex mosaicism consisting of (1) 47,XXX cells with a single copy of SRY (n = 177), two copies of SRY (n = 3), and no SRY (n = 1); (2) 46,XX cells with a single copy of SRY (n = 9) and no SRY (n = 3); (3) 45,X cells with no SRY (n = 5); and (4) 48,XXXX cells with a single copy of SRY (n = 1) and two copies of SRY (n = 1). PCR analysis showed the presence of Yp portion with the breakpoint between DYS264 and AMELY. Microsatellite analysis demonstrated three alleles for DMD and AR. X-inactivation analysis for the methylation status of the AR gene showed random inactivation of the three X chromosomes. The results suggest that this 47,XXX male has resulted from abnormal X-Y interchange during paternal meiosis and X-X nondisjunction during maternal meiosis. Complex mosaicism may be due to the age-related increase in mitotic nondisjunction which is prone to occur in rapidly dividing lymphocytes and to the presence of two randomly inactivated X chromosomes which may behave asynchronously during mitosis, and clinical features of this male would primarily be explained by the genetic information on the SRY (+) der(X) chromosome and his advanced age.

Analysis of two 47,XXX males reveals X-Y interchange and maternal or paternal nondisjunction

Two cases of 47,XXX males were studied, one of which has been published previously (Bigozzi et al. 1980). Analysis of X-linked restriction fragment length polymorphisms revealed that in this case, one X chromosome was of paternal and two were of maternal origin, whereas in the other case, two X chromosomes were of paternal and one of maternal origin. Southern blot analysis with Y-specific DNA probes demonstrated the presence of Y short arm sequences in both XXX males. In one case, the results obtained pointed to a paracentric inversion on Yp of the patient's father. In situ hybridization indicated that the Y-specific DNA sequences were localized on Xp22.3 in one of the three X chromosomes in both cases. The presence of Y DNA had no effect on random X inactivation. It is concluded that both XXX males originate from aberrant X-Y interchange during paternal meiosis, with coincident nondisjunction of the X chromosome during maternal meiosis in case 1, and during paternal meiosis II in case 2.

Y-specific DNA sequences in male patients with 46,XX and 47,XXX karyotypes

Y chromosomal DNA sequences were detected in three of four 46,XX males and in one 47,XXX male. One reiterated Y chromosomal sequence, Y-190, was localized by in situ hybridization to the distal short arm of an X chromosome of the 47,XXX male. This result is compatible with the hypothesis that an aberrant X/Y interchange has occurred, most likely during paternal meiosis, and that this interchange accounts for Y chromosomal material and sex reversal in this 47,XXX individual.

An XXX male resulting from paternal X-Y interchange and maternal X-X nondisjunction

A 2-year-old boy was found to have a 47,XXX karyotype. Restriction-fragment-length-polymorphism analysis showed that, of his three X chromosomes, one is of paternal and two are of maternal origin. The results of Y-DNA hybridization were reminiscent of those in XX males in two respects. First, hybridization to Southern transfers revealed the presence in this XXX male of sequences derived from the Y-chromosomal short arm. Second, in situ hybridization showed that this Y DNA was located on the tip of the X-chromosomal short arm. We conclude that this XXX male resulted from the coincidence of X-X nondisjunction during maternal meiosis and aberrant X-Y interchange either during or prior to paternal meiosis.