1 - Departamento de Endocrinologia, Hospital das Forças Armadas (HFAR)
2 - Unidade de Endocrinologia Pediátrica, Hospital de Dona Estefânia, Centro Hospitalar Universitário de Lisboa Central (CHULC), Lisboa, Portugal
3 - Unidade de Reumatologia Pediátrica, Hospital de Dona Estefânia, Centro Hospitalar Universitário de Lisboa Central (CHULC), Lisboa, Portugal
4 - Departamento de Genética Humana, Instituto Nacional de Saúde Dr. Ricardo Jorge, Lisboa, Portugal
- Publicação em versão integral na revista Journal of Pediatric Endocrinology and Metabolism
Objectives: Congenital Adrenal Hyperplasia (CAH) is a group of genetic diseases characterized by impaired cortisol biosynthesis. 95% of CAH cases result from muta- tion in the CYP21A2 gene encoding 21-hydroxilase. TNX-B gene partially overlaps CYP21A2 and encodes a matrix protein called Tenascin-X (TNX). Complete tenascin defi- ciency 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.
Case presentation: We report four patients heterozygous for a CAH-X CH-1 allele that do not present clinical manifestations of the EDS.
Conclusions: All CAH patients, carriers of these TNXA/ TNXB chimeras, should be evaluated for clinical manifes- tations related to connective tissue hypermobility, cardiac abnormalities and other EDS features, allowing for better clinical surveillance management.
Palavras Chave: CAH-X syndrome; CYP21A2 gene; tenascin-X.