The prevalence of isolated growth hormone deficiency among children of short stature in Jordan and its relationship with consanguinity.

Objective: The prevalence of isolated growth hormone deficiency (IGHD) among short-statured children in Jordan, where consanguineous marriage (CM) is common, is unknown. No studies have investigated the relationship between degrees of consanguinity and IGHD. This study aimed to determine the prevalence of IGHD among short-statured children referred to a university hospital in Jordan and its relationship with different degrees of consanguinity.

Design: We conducted a 24-month cross-sectional observational trial at an outpatient tertiary care center in Amman, Jordan.

Patients: We obtained detailed family histories, medical evaluations and laboratory tests for 94 short-statured children (50 boys and 44 girls aged 6-16 years).

Measurements: Complete and partial GHD were defined as peak GH responses of 5 and 7 μg/l (15 and 21 mIU/l) [IRMA/DiaSorin®], respectively, in both exercise and insulin tolerance tests.

Results: GHD was diagnosed in 69·1% of the short children, including 86% (43/50) of the children of consanguineous parents (83·3%, 93·8% and 81·8% of children of first cousins, first cousins once removed and second cousins, respectively) and 50% (20/44) of the children of nonconsanguineous parents (P = 0·039, 0·002 and 0·013, respectively). However, there was no statistically significant difference in the prevalence of small pituitary MRI between GH-deficient children of consanguineous parents and those of nonconsanguineous parents (28·6% vs 13·6%, P = 0·3).

Conclusions: The prevalence of IGHD among referred short children in Jordan was exceptionally high and significantly higher in the children of CM. In countries where CM is common, preconception counselling and rigorous surveillance for GHD in short children may be indicated.