The role of Yp in sex determination: New evidence from X/Y translocations

Abstract

A 33-year-old man had azoospermia and tubular atrophy as in the Klinefelter syndrome but short stature. He had a 46,X,t(X/Y) (Xqter lead to p22.3::Yp11 lead to Yqter) translocation and was H-Y antigen-positive. This excludes one of the genes controlling H-Y antigen from the terminal portion of the short arm of the Y chromosome. This case and the two similar ones in the literature indicate that the proximal Yp portion is required for the differentiation of a male gonad. The pattern of X inactivation was random in the patient's fibroblasts, whereas in the lymphocytes the translocated chromosome was preferentially inactivated; comparison with other cases shows that the quantity of Y chromosome material involved in these translocations does not influence the X inactivation patterns. In the three cases with this dicentric translocation the X chromosome centromere is consistently the active one. Our case indicates that the choice of which centromere is inactivated is independent of the replication pattern of the X chromosome. Our patient and a few other relevant cases from the literature confirm that factors controlling height are located on the distal portion of Xp and of Yp.

Contiguous gene syndromes due to deletions in the distal short arm of the human X chromosome.

“…However, his first cousin, also affected by the same chromosomal abnormality, was below the 3rd centile for height when observed at age 6 yr and 6 mo. SS has been described in the original reports of cases 1 (20), 11 (12), 15 (19), and 16 (14). In patients 2, 6, and 9 the height was 131, 65, and 108 cm at age 13 yr (<3rd centile), 8 mo (12).…”

Familial X;Y translocation in a malformed male infant and his mother

“…Since X-linked ichthyosis is due to steroid sulfatase deficiency, it is probable that ichthyosis would have occurred, had he survived. Steroid sulfatase activity was examined in six familial cases, including our case (Speevak et aI., 1985;Ross et al, 1985;Boyd et al, 1981;Metaxotou et at., 1983;Tiepolo et at., 1980) and one sporadic case (Zuffardi et al, 1982). Among these cases, steroid sulfatase activity in female carriers except for those reported by Speevak et al (1985) showed a value half that of normal females, and was almost zero in male patients.…”

“…Among those reported in the literature, four phenotypic male patients having a normal X chromosome are included. Although the karyotype of the patient reported by Bernstein et al (1978) was stated to be 46,X,t(X;Y)(p22;ql 1), it is possible that it could be reinterpreted to have been Yp (Zuffardi et al, 1982). In other two cases (Bernstein et al, 1980;Zuffardi et at., 1982), Yp was contained in the X;Y translocation chromosome.…”

“…Although the karyotype of the patient reported by Bernstein et al (1978) was stated to be 46,X,t(X;Y)(p22;ql 1), it is possible that it could be reinterpreted to have been Yp (Zuffardi et al, 1982). In other two cases (Bernstein et al, 1980;Zuffardi et at., 1982), Yp was contained in the X;Y translocation chromosome. Since the penetrance of male-determining genes on the Y chromosome is strong (Ohno, 1976), existence of Yp brings about male manifestation.…”

Sexo ambiguo con constitución cromosómica 45,X/45,X,t(Y;14)

“…Esta parece ser la unica funcion genetica del cromosoma Y, ya que la diferenciacion mascultna se efectua bajo la influencia de androgenos secretados por los testi'culos 9 . Si solo existe Yq, los pacientes son de sexo femenino y la translocacion puede ser trasmitida a hijos hombres o mujeres 6 . El mosaicismo consiste en la presencia simul- tanea de dos o mas h'neas celulares diferentes en un individuo.…”