Background: In the absence of a national screening program for congenital adrenal hyperplasia (CAH), children are often diagnosed late, when unwell with salt-wasting crisis or hypoglycemic symptoms. In 21-hydroxylase deficient CAH (21OHD-CAH), girls usually present with a disorder of sex development (DSD) and are thus diagnosed earlier than boys who present with salt-wasting.
Aim: To investigate the global intelligence of children with classical congenital adrenal hyperplasia and to evaluate the relation between intelligence quotient (IQ), sex and age at diagnosis
Patients and Methods: Patients with 21OH-CAH were evaluated for cognitive function by the same psychologist in a single center. IQ was assessed using the Wechsler Intelligence Scale for Children (Wechsler Preschool and Primary Scales of Intelligence (WPPSI)) and the Khos Block Design Test for preschool children. Degrees of intellectual disability or normal intelligence were defined according to IQ value, a child with an IQ < 70 being considered to have intellectual disability. Epi-info7 software was used to collect the data and perform statistical tests.
Results: Sixty-six patients (18 boys and 48 girls, M:F ratio 0.4) with classical 21OHD-CAH deficiency were evaluated. Girls were both diagnosed earlier and started treatment earlier than boys: median (range) 17.5 (1-540) vs 45 (8-1645) days. Mean (SD) age at IQ evaluation was 7.8±3.4 years, with no difference in age at IQ evaluation between girls and boys (7.5±3 vs 8.8±4 years, P=0.2). Mean IQ was 78 ±18.8 in all children. The distribution of patients was:
• 20 <IQ<34 (Severe intellectual disability): 2 (3%)
• 34<IQ<49 (Moderate intellectual disability): 4 (6%)
• 50<IQ<69 (Mild intellectual disability):16 (23%)
• 70<IQ<85: (Low intelligence): 22 (33%)
• 85<IQ<99: (Low-average intelligence): 14 (21%)
• 100<IQ<114 (Above average intelligence): 9 (13.5%) IQ was significantly higher in girls than boys - mean (SD) 80.1±16.5 vs 65.9±20.6 (P< 0.02). Also, there was a correlation between IQ and age at diagnosis and start of treatment (ρ: -0.29 IC 95%[-0.4972 ; -0.0516], P< 0.02).
Conclusion: Children with 21OHD-CAH deficiency usually have lower IQ than the general population, with boys more severely affected than girls. This is probably related to delayed diagnosis in the absence of DSD in boys, and the consequent delay in starting treatment. Our findings underline the importance of implementing a neonatal screening program for CAH in all the countries where this condition is relatively common.
15 Sep 2022 - 17 Sep 2022