0000000000648651
AUTHOR
Johnny Deladoëy
Developmental Abnormalities of the Thyroid
Developmental anomalies of the thyroid gland (thyroid dysgenesis) underlie the majority of cases of congenital hypothyroidism. Only a small number of monogenic defects have been shown to result in athyreosis or orthotopic thyroid hyperplasia, whereas the commonest developmental anomaly, thyroid ectopy, remains unexplained. Ectopy may result from multiple genetic or epigenetic hits in the germline and/or at the somatic level. This chapter gives a brief overview of the monogenic defects in candidate genes that have been identified so far and of the syndromes that are known to be associated with thyroid dysgenesis. In addition, we discuss gain-of-function mutations of the thyroid hormone stimu…
Pseudodominant inheritance of goitrous congenital hypothyroidism caused by TPO mutations: molecular and in silico studies.
CONTEXT AND OBJECTIVE: Most cases of goitrous congenital hypothyroidism (CH) from thyroid dyshormonogenesis 1) follow a recessive mode of inheritance and 2) are due to mutations in the thyroid peroxidase gene (TPO). We report the genetic mechanism underlying the apparently dominant inheritance of goitrous CH in a nonconsanguineous family of French Canadian origin. DESIGN, SETTING, AND PARTICIPANTS: Two brothers identified by newborn TSH screening had severe hypothyroidism and a goiter with increased (99m)Tc uptake. The mother was euthyroid, but the father and two paternal uncles had also been diagnosed with goitrous CH. After having excluded PAX8 gene mutations, we hypothesized that the und…
Non-Immune Goiter and Hypothyroidism in a 19-Week Fetus: A Plea for Conservative Treatment
Hypothyroidism was documented by cordocentesis at 19 weeks in a fetus with non-immune goiter. Intra-amniotic thyroxine was injected at 25 weeks when amniotic fluid volume increased. Psychomotor outcome was normal. We argue that intra-amniotic thyroxine should not be used to treat the hypothyroidism but only to correct the development of polyhydramnios.