Paediatric Endocrinology Unit, Université Libre de Bruxelles (ULB), Hôpital Universitaire de Bruxelles (H.U.B.), Hôpital Universitaire des Enfants Reine Fabiola (HUDERF), 1020 Bruxelles, Belgium.
Genetics Department, Université Libre de Bruxelles (ULB), Hôpital Universitaire de Bruxelles (H.U.B), Hôpital Universitaire des Enfants Reine Fabiola (HUDERF), 1020 Bruxelles, Belgium.
Eur J Endocrinol. 2024 Aug 5;191(2):K5-K9. doi: 10.1093/ejendo/lvae100.
Biallelic loss-of-function variants in the IYD gene cause hypothyroidism resulting from iodine wasting. We describe 8 patients (from 4 families in which the parents are first cousins) who are homozygous for a variant in IYD (including a novel missense deleterious variant, c.791C>T [P264L], in 1 family). Seven patients presented between 5 and 16 years of age with a large goiter, overt hypothyroidism, and a high serum thyroglobulin. The goiter subsided with levothyroxine therapy in most. Upon stopping levothyroxine in 5 patients, goiter and hypothyroidism reappeared in 3. In these 3 patients, a rising serum thyroglobulin concentration preceded hypothyroidism and goiter and urinary iodine excretion was low. In patients who remained euthyroid, urinary iodine was normal. In conclusion, these patients bearing biallelic pathogenic variants in IYD developed a large goiter, a high serum thyroglobulin, and overt hypothyroidism when their iodine intake was low.
IYD 基因的双等位基因失活变异可导致碘消耗引起的甲状腺功能减退症。我们描述了 8 名患者（来自 4 个家系，这些家系中的父母是第一代表亲），他们均为 IYD 基因的纯合变异（包括 1 个家系中的新型错义有害变异 c.791C>T [P264L]）。7 名患者在 5 至 16 岁时出现大甲状腺肿、明显甲状腺功能减退和血清甲状腺球蛋白升高。左旋甲状腺素治疗后，大多数患者的甲状腺肿消退。在 5 名患者停止左旋甲状腺素治疗后，3 名患者的甲状腺肿和甲状腺功能减退再次出现。在这 3 名患者中，血清甲状腺球蛋白浓度升高先于甲状腺功能减退和甲状腺肿，尿碘排泄减少。在保持甲状腺功能正常的患者中，尿碘正常。总之，这些患者携带 IYD 基因的双等位基因致病性变异，当碘摄入不足时，会出现大甲状腺肿、血清甲状腺球蛋白升高和明显的甲状腺功能减退。
