Ivo Catarina Rodrigues, Fitas Ana Laura, Madureira Inês, Diamantino Catarina, Gomes Susana, Gonçalves João, Lopes Lurdes
Departamento de Endocrinologia, Hospital das Forças Armadas (HFAR), Lisboa, Portugal.
Unidade de Endocrinologia Pediátrica, Hospital de Dona Estefânia, Centro Hospitalar Universitário de Lisboa Central (CHULC), Lisboa, Portugal.
J Pediatr Endocrinol Metab. 2022 Oct 20;36(1):81-85. doi: 10.1515/jpem-2022-0396. Print 2023 Jan 27.
Congenital Adrenal Hyperplasia (CAH) is a group of genetic diseases characterized by impaired cortisol biosynthesis. 95% of CAH cases result from mutation in the CYP21A2 gene encoding 21-hydroxilase. TNX-B gene partially overlaps CYP21A2 and encodes a matrix protein called Tenascin-X (TNX). Complete tenascin deficiency causes Enlers-Danlos syndrome (EDS). A mono allelic variant called CAH-X CH-1 was recently described, resulting from a CYP21A2 complete deletion that extends into the TNXB. This haploinsufficiency of TNX may be associated with a mild hypermobility form of EDS, as well as other connective tissue comorbidities such as hernia, cardiac defects and chronic arthralgia.
We report four patients heterozygous for a CAH-X CH-1 allele that do not present clinical manifestations of the EDS.
All CAH patients, carriers of these TNXA/TNXB chimeras, should be evaluated for clinical manifestations related to connective tissue hypermobility, cardiac abnormalities and other EDS features, allowing for better clinical surveillance management.
先天性肾上腺皮质增生症（CAH）是一组以皮质醇生物合成受损为特征的遗传性疾病。95%的CAH病例是由编码21-羟化酶的CYP21A2基因突变引起的。TNX-B基因部分重叠于CYP21A2基因，并编码一种名为腱生蛋白-X（TNX）的基质蛋白。完全缺乏腱生蛋白会导致埃勒斯-当洛综合征（EDS）。最近描述了一种名为CAH-X CH-1的单等位基因变异，它是由延伸至TNXB的CYP21A2基因完全缺失引起的。TNX的这种单倍体不足可能与EDS的轻度关节过度活动形式以及其他结缔组织合并症（如疝气、心脏缺陷和慢性关节痛）有关。
我们报告了4例携带CAH-X CH-1等位基因杂合子的患者，他们没有出现EDS的临床表现。
所有携带这些TNXA/TNXB嵌合体的CAH患者，都应评估其与结缔组织过度活动、心脏异常及其他EDS特征相关的临床表现，以便进行更好的临床监测管理。
