Ambiguous genitalia by 9p deletion inherent to a dic(Y;9)(q12;p24).
We describe here a 3-month-old male infant with brachy-plagyocephaly, short neck, widely spaced nipples, mild hypertonia, and ambiguous external genitalia but with both testes in the scrotum and no Müllerian derivates. His karyotype was 45,X,der(Y;9)(q12;p24).ish der(Y;9)(DYZ3+,SRY+,9ptel-) de novo. This patient's impaired sex differentiation is consistent with gonadal dysgenesis and compares with the male-to-female sex reversal secondary to a partial 9p deletion in spite of an intact Yp or SRY locus documented in 24 patients including a sex-reversed girl with a (Y;9) dicentric derivative. As for the cytogenetic findings, this case represents the second instance of a de novo pseudodicentric (Y;9) chromosome with loss of both distal 9p and Yq12 regions, apparent intactness of SRY, and consistent or preferential inactivation of the Y centromere. In addition, the possible 9p23p-p22 duplication observed in this case evokes the concomitant 9p22-p21 duplication documented in the previous girl with a (Y;9) derivative. Hence, these striking similarities point to a nonrandom Y;9 rearrangement in patients with either sex reversal or gonadal dysgenesis. Even if the present pseudodicentric derivative had inactivated the Y centromere, the existence of some variant cells points to functional dicentricity as it has been documented in other Y;autosome dicentric derivatives.
Vásquez-Velásquez
Ana I
AI
Centro de Investigación Biomédica de Occidente, Instituto Mexicano del Seguro Social, Ap. Postal 2-3838, Guadalajara, Jal., México.
Arnaud-López
Lisette
L
Figuera
Luis E
LE
Padilla-Gutiérrez
Jorge R
JR
Rivas
Fernando
F
Rivera
Horacio
H
D000015:Abnormalities, Multiple / Q000235:genetics* / Q000473:pathology; D002899:Chromosomes, Human, Pair 9 / Q000235:genetics*; D041322:Chromosomes, Human, Y / Q000235:genetics*; D005837:Genitalia, Male / Q000002:abnormalities* / Q000473:pathology; D006801:Humans; D007223:Infant; D007621:Karyotyping; D008297:Male; D008800:Mexico; D014178:Translocation, Genetic / Q000235:genetics*