Identification of A Novel Hemizygous SLC16A2 Nonsense Mutation in Allen-Herndon-Dudley Syndrome

Year 2022, Volume: 3 Issue: 2, 219 - 222, 01.08.2022

Ayça Kocaağa , Sevgi Yimenicioğlu , Veysel Nijat Baş , Oğuz Çilingir , Yaşar Bildirici

Abstract

Allan-Herndon-Dudley syndrome (AHDS) is a rare X-linked inherited disease that prevents absorption of thyroid hormone and causes axial hypotonia, weakness, and severe intellectual disability. The syndrome is caused by mutations in the SLC16A2 (known as MCT8) gene. This gene encodes the brain transporter of thyroid hormones. Deficiency of MCT8 leads to a lack of T3 entry in the brain, which causes central hypothyroidism. We described a boy who manifested congenital hypotonia, severe developmental delay, mental retardation, muscle weakness, and dystonia. He was diagnosed with AHDS which details the clinical and biochemical findings. A novel pathogenic nonsense (c.25G>T;p.E9X) mutation in the SLC16A2 gene was identified by direct sequencing. This case can expand the mutational spectrum of SLC16A2 gene mutations and support the clinical features of AHDS.

Keywords

MCT 8 defficiency, Hypotonia, SLC16A2 Gene, Thyroid hormone abnormality.

Allen-Herndon-Dudley Sendromunda yeni Bir Hemizigot SLC16A2 nonsense mutasyonu

Abstract

Allan-Herndon-Dudley sendromu (AHDS), tiroid hormonunun emilimini önleyen ve aksiyal hipotoni, güçsüzlük ve ciddi zihinsel yetersizliğe yol açan, X'e bağlı, nadir görülen bir kalıtsal hastalıktır. SLC16A2 (MCT8 olarak bilinir) genindeki mutasyonlar hastalığa neden olmaktadır. Bu gen, tiroid hormonlarının beyine transferini sağlayan bir proteini kodlar. MCT8 eksikliği, beyinde merkezi hipotiroidizme neden olan T3 girişi eksikliğine yol açar. Doğuştan hipotoni, ciddi gelişim geriliği, zeka geriliği, kas güçsüzlüğü ve distoni ile kendini gösteren kliniğe sahip bir erkek çocuğu tanımladık. AHDS teşhisi kondu, klinik ve biyokimyasal bulguları detaylandırıldı. SLC16A2 genindeki yeni bir patojenik anlamsız (c.25G>T;p.E9X) mutasyon, SLC16A2 gen dizi analizi ile tanımlandı. Bu vaka, SLC16A2 gen mutasyonlarının mutasyonel spektrumunu genişletebilir ve AHDS'nin klinik özelliklerini destekleyebilir.

Keywords

MCT 8 eksikliği, Hipotoni, SLC16A2 Geni, Tiroid hormonu anormalliği.

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