Testicular histology in boys with Prader-Willi syndrome: fertile or infertile?
OBJECTIVE
Prader-Willi syndrome is associated with hypogonadism. Cryptorchidism is found in 93% of cases and considered a phenotypic criterion. Men with Prader-Willi syndrome are thought to be infertile. To study the fertility probability in boys with Prader-Willi syndrome we analyzed testicular histology in 8 prepubertal boys and 1 man.


METHODS
Eight boys 16 months to 14 years old with a proven molecular diagnosis of Prader-Willi syndrome, including 6 with a deletion on chromosome 15 and 2 with uniparental maternal disomy of chromosome 15, underwent orchiopexy and the man underwent unilateral orchiectomy. Prepubertal testes were classified into 4 Nistal categories according to mean tubular diameter, the tubular fertility index (average percent of tubules containing spermatogonia) and the Sertoli's cell index.


RESULTS
Two of 8 prepubertal boys showed a favorable Nistal score of I, 1 showed a Nistal score of II and 5 showed a Nistal score of III. The testis in the man showed diffuse tubular atrophy with tubular hyalinization, a Sertoli's cell nodule, vacuolized Leydig cells, peritubular hyalinization and small tubuli.


CONCLUSIONS
Prader-Willi syndrome appears to be a heterogenic disorder with respect to testicular histology. Although most boys showed absent spermatogonia, 2 of 8 had normal testicular histology. Therefore, it is suggested that it is uncertain what the fertility outcome is in boys with Prader-Willi syndrome.
Vogels
Annick
A
Department of Human Genetics, University Hospitals Leuven, Leuven, Belgium.
Moerman
Philippe
P
Frijns
Jean-Pierre
JP
Bogaert
Guy A
GA
D000293:Adolescent; D001284:Atrophy; D002648:Child; D002675:Child, Preschool; D006801:Humans; D007223:Infant; D007248:Infertility, Male / Q000209:etiology*; D008297:Male; D011218:Prader-Willi Syndrome / Q000150:complications* / Q000473:pathology* / Q000503:physiopathology; D012671:Seminiferous Tubules / Q000473:pathology; D054331:Sertoli Cell-Only Syndrome / Q000473:pathology; D013091:Spermatogenesis; D013737:Testis / Q000473:pathology*