Hyperextensibility with normal elastic recoil is a feature of aEUR'

Ehlers Danlos syndrome Ehlers - Danlos syndrome (EDS) Ehler's danlos syndrome comprise a clinically and genetically heterogenous group of disorder that result from some defect in the synthesis or structure of fibrillar collagen. The basic abnormality in Ehler's Danlos syndrome (EDS) is some defect in the synthesis or structure of collagen Biosynthesis of collagen is a complex process It involves numerous structural collagen genes or enzymes. Which are used in post transcriptional modification of collagen. Therefore it can be disturbed by no. of genetic errors that may affect any of the numerous genes or enzymes necessary for collagen synthesis. At the molecular level, a variety of defects, varying .from mutations involving structural genes or collagens to those involving enzymes that are responsible for post transcriptional modification of mRNA have been detected. Such molecular heterogenecity result in expression of EDS as a clinically variable disorder with several patterns of inheritance. On the basis of clinical and molecular characteristics six variants of Ehler's Danlos syndrome have been identified. The common thread in all forms of EDS is some abnormality in the synthesis of collagen. Clinical features - As might be expected tissues rich in collagen such as skin, ligaments and joints are frequently involved. - Because the abnormal collagen fibre lacks adequate tensile strength, skin is hyper extensible and the joints are hypermobile. The skin is extraordinarily stretchaeble, extremely fragile and vulnerable to trauma. - Minor injuries produce gaping defects and surgical repair or intervention is accomplished with great difficulty because of the lack of normal tensile strength. - The defect in connective tissue may lead to serious internal complications which include:? - Rupture of the colon and large aeries - Occular.fragility with rupture of cornea and retinal detachment - Diaphragmatic hernia EQS type Gene defect Inheritance Clinical findings Classical Defect in type V collagen Mutation in COL5A gene Autosomal dominant Skin and joint hypermo? bility, atrophic scars, Easy bruising Hypermobility Unknow Autosomal dominant Joint hypennobility, pain, dislocations Vascular Defect in collagen type 111 Autosomal The skin, aerial or Collagen ill is abundant in Blood vessels and intestine ( *.. severe defect of these organs dominants uterine rupture, bru? ising, small joint hyperextensibility Kyphoscoliosis Reduced level of lysyl hydroxylase essential for cross linking of collagen fibres Autosomal recessive Hypotonia, joint laxity, congenital scoliosis, ocular fragility Ahrochalasia - Defect in conversion of Autosomal Severe joint hypenno? Procollagen to collagen - Results from mutation in COL IA, and COL1 A2 dominant bility, skin changes mild, scoliosis, bruising Dermatospra- xias Mutation in the procollagen N peptidase gene. Autosomal Recessive Severe skin fragility, cutis laxa, bruising Cutis laxa The inelastic hyperextensible skin fails to resume its normal shape after stretching and hence appears pendulous. Therefore affected newborn infants appear "prematurely aged". The skin abnormality is most prominent around eye, face neck. Therefore patients with cutis laxa have characteristic facial features including an aged appearance with sagging jaws (blood hound appearance) a hooked nose with eveed nostrils, a sho columella, a long upper lip and eveed lower eyelids. Hypermobility of the joint is not present. Pseudoxanthoma elasticum It is a rare group of disorders affecting the elastic tissue. It primarily affects the dermis, retina, and cardiovascular system. The skin has characteristic "plucked chicken skin" appearance. - It tends to loose its elastic recoil when stretched.