Intrauterine therapy of goitrous hypothyroidism in a boy with a new compound heterozygous mutation (Y453D and C800R) in the thyroid peroxidase gene. A long-term follow-up.

We report the results of intrauterine L-thyroxine therapy, and the long-term follow-up in a fetus who presented at 32 weeks' gestation with goitrous hypothyroidism, hyperextension of the neck, and polyhydramnios. Spontaneous delivery was possible and hypothyroidism improved. Molecular analysis revealed a new compound heterozygous mutation (Y453D/C800R) in the TPO gene.