Factors and markers of growth hormone secretion and gonadal function in Fanconi anemia

Many factors may be involved in the growth and gonadal dysfunction of Fanconi anemia (FA).

To evaluate the (1) relationship between FA presentation, including genital abnormalities and pituitary stalk interruption syndrome (PSIS), (2) markers of growth hormone (GH) deficiency and gonadal function, and (3) factors influencing final height and gonadal function.

Twenty five patients with FA were included, 17 of them were given bone marrow transplantation.

Six patients were diagnosed with GH deficiency and PSIS (group A), whereas 19 had no evidence of GH deficiency (group B). In group A, all patients had more than 3 FA malformations and all 5 boys had cryptorchidism associated with microphallus in 4. All patients had heights and plasma insulin-like growth factor I < -3SD. Final height was reached in 15 patients and was < or = -2SD in 12 of them, all but 3 were born small for gestational age and/or given norethandrolone and/or corticosteroids. Gonadal function was abnormal in 5/7 boys and 4/5 girls evaluated at pubertal age. The plasma concentrations were low in 4/9 for antimüllerian hormone and in 3/9 for inhibin B, 3 of them had been given bone marrow transplantation.

PSIS can be part of a severe FA phenotype. It seems to occur mainly in boys, with more than 3 malformations, microphallus and cryptorchidism. This phenotype is associated with normal blood counts, defining a new clinical subgroup of patients.