ESPE Abstracts

Background: In bilateral anorchia or vanishing testes syndrome, testicular function is normal during the embryonic period, as shown by the absence of Müllerian remnants and of hypospadias. Although normally differentiated, the penis may be small due to decreased testosterone secretion during the fetal period. In a normally virilised boy with non-palpable testes, with or without micropenis, the diagnosis is established by undetectable plasma anti-Müllerian hormone (AMH) and absent Müllerian structures. The syndrome is thought to result from vascular obstruction and/or torsion. We report two unrelated families in which one sibling presented with bilateral anorchia diagnosed in infancy and one sibling with testicular torsion at adolescence.

Patients and Methods: retrospective case series. Setting: paediatric endocrinology units of two academic hospitals (Sainte-Justine, Montreal, Quebec, Canada and HUDERF, Bruxelles, Belgium). Family 1 (HUDERF, Belgium): A 10-month-old boy was referred for bilateral cryptorchidism. His parents are healthy, non-consanguineous, of Spanish and Congo-Brazzaville origin. There was a family history of cryptorchidism in the paternal uncle and his son. The mother had taken paroxetine during pregnancy. The index case was born at term (38 weeks, 3240 g, 47 cm). Very small testes had reportedly been palpated in the neonatal period. At 10 months of age, physical examination was normal except for non-palpable testes. Plasma AMH level was undetectable and gonadotrophins were very elevated (FSH: , LH mU/l, repectively). At 14 years of age, an older brother presented with bilateral scrotal oedema (confirmed by ultrasound) and was initially treated with antibiotics. A right testicular torsion developed and bilateral orchidopexy was performed. Family 2 (Sainte-Justine, Canada): The index case, a boy referred at 3-days of age for micropenis, has been reported previously (Stoppa-Vaucher et al, Clin Biochem 43: 1373, 2010). Subsequent to this publication, we learned that one of his brothers presented at age 15 years with three episodes of left testicular torsion that led to bilateral orchidopexy.

Discussion: Testicular torsion is familial in 10 % of the cases. Most cases of testicular torsion occur during adolescence. In these adolescents, an anatomical variant called the clapper bell anomaly renders the testis more mobile, predisposing it for torsion. By contrast, antenatal torsion does not seem to be associated with this anomaly. However, the present report of two families with congenital anorchia in one sibling and testicular torsion at adolescence in another suggests that both conditions represent a spectrum with a shared genetic predisposing factor.