Background: The outcome of congenital hypothyroidism (CH) has dramatically changed since the start of neonatal screening. However the benefit of this program is not felt in Algeria and other countries where the pathology is still causing irreparable brain damage.
Objective and hypotheses: To evaluate age at diagnosis of CH and its impact on the mental development in the absence of new-born screening.
Method: Case notes of all patients referred to our Endocrine Clinic for congenital hypothyroidism (CH) were reviewed. Patients with Downs syndrome were not included in the study. True congenital hypothyroidism was diagnosed when imaging showed thyroid dysgenesis or dyshormonogenesis; or when venous TSH was >50 mU/L with subnormal fT4 (< pmol/L) in healthy term babies in whom imaging was not performed. Developmental delay was classified as severe, moderate and mild, and analysed according to age at starting treatment (< 1 month, 13 months, 36 months, >6 months); and to initial venous fT4.
Results: Of 75 patients referred with elevated TSH 56 (F36:M20) had true CH. Mean (range) age at referral was 17.6 (0.4138) months at which time 21 (37.5%) patients were already on treatment. Mean (range) fT4 at diagnosis was 5.9 (0.0120.5) pmol/L, TSH: 132.6(5.741075) mU/L. Aetiologies were thyroid dysgenesis (29) due to hypoplasia (13), athyreosis (12) and ectopia (4); dyshormonogenesis (10) and unknown causes (16). Mean age at starting treatment was 10.38 months (0.3138). Breakdown of age (months) at starting treatment/initial fT4 (pmol/L) (n) was <1/5.25 (12), 13/10.7 (20), 36/1013(10) and >6 m/13.5 (14). Mental delay was considered severe in 5(8.9%) patients, moderate in 16 (28.6%) and mild in 3(5.3%). Severe mental delay was highly correlated with initial ft4 levels: 3.83 pmol/l (0.9910.7) and age at starting treatment: 11 (0.540) months.
Conclusion: Diagnosis of CH is still considerably delayed in countries where newborn screening is absent, leading to mental impairment in affected children. Algerian paediatrician are seriously concerned by this situation and are actively working to set-up a national screening program.
10 - 12 Sep 2016
European Society for Paediatric Endocrinology