Family history of thyroid disease and risk of congenital hypothyroidism in neonates with Down síndrome.

INTRODUCTION

Family history of thyroid disease (FHTD) constitutes a possible risk factor for congenital hypothyroidism (CH) in the general population; however, FHTD possible relationship with CH in subjects with Down syndrome (DS) has not yet been explored.

OBJECTIVE

To determine whether FHTD is associated with an increased incidence of CH in neonates with DS.

METHOD: Hospital-based case-control study in 220 neonates with DS. Thyroid function tests of 37 infants with DS and positive FHTD (cases) were compared with those of 183 newborns with DS without FHTD (control group). Data were analyzed using multivariate logistic regression analysis and adjusted odds ratios (aORs) with their respective 95 % confidence intervals (CI) were calculated.

RESULTS

Nine newborns with DS in our sample had CH (4.1 %). In the multivariate analysis, FHTD showed an association with CH in neonates with DS (aOR = 8.3, 95 % CI: 2.0-34.3), particularly in males (aOR = 9.0, 95 % CI: 1.6-49.6). In contrast, newborns with DS without FHTD were less likely to suffer from CH (aOR = 0.4, 95 % CI: 0.1-0.8).

CONCLUSIONS

Newborns with DS and FHTD have an eight-fold higher risk for CH, particularly when the index case is male. FHTD detailed evaluation can be an easy and accessible strategy to identify those newborns with DS at higher risk for CH.