Genetics of ehlers-danlos syndrome

Abstract

Ehlers-Danlos Syndrome (EDS) is a genetic condition characterized characterized by join hypermobility, skin hyperextension, and tissue fragility that affects the connective tissue and collagen structures in the human body. The prevalence has been reported as in 1 in 5000 births and affects equally in both sexes. EDS has no racial proportions. There are several types of EDS, that are based on the 2017 International Ehlers-Danlos Syndrome Classification. Thin and fragile mucosa, bleeding tendency, periodontal tissue injuries, and also tongue ghorlin syndrome has been reported as the intraoral manifestations in EDS. Another manifestation is hypermobile temporomandibular joint with high incidence of subluxation and dislocation. The mechanism of Ehlers-Danlos Syndrome is connected to collagen biosyhntesis, originating with nucleus transcription to aggregate collagen heterotrimers into large fibrils. Mutations have been found in collagen-encoding genes for several of these forms, or in genes encoding collagen-modifying enzymes. One of the most common type of EDS is classical EDS which is having type V collagen deficiency. This is caused by mutation in type V collagen-encoding gene, COL5A1 dan COL5A2. Type V collagen is a regulatory collagen fibril that forms the basis of the fibrils in bony, cartilaginous, fibrous, and tubular structures. The majority of mutations have been reported are nonsense mutations; splice site mutations leading to exon skips, missense mutations causing glycine substitutions, and frameshift mutation. As a clinician, the knowledge about the etiology, clinical sign, oral manifestation, and the genetic aspect of this syndrome is crucial for making correct diagnoses and proper treatment planning. In this review, the author will explain further about the genetic aspects of Ehlers-Danlos Syndrome.