(1) Autosomal dominant hereditary skin relaxation: Autosomal dominant hereditary skin relaxation is usually mild, and skin lesions mainly involve the skin, showing typical facial changes and wrinkles caused by systemic skin relaxation, sometimes accompanied by gastrointestinal diverticulum hernia or pelvic organ prolapse. Rare complications include pulmonary artery stenosis, aorta and aortic dilatation, bronchiectasis and emphysema. Early diagnosis can often be made according to excessive skin wrinkles and loose skin. Most patients with autosomal dominant cutaneous relaxation are related to mutation of ELN gene. The mutation of ELN gene leads to abnormal synthesis and secretion of elastin and participates in the formation of elastic matrix, thus changing the structure of elastic fibers and causing diseases. Some scholars have also reported autosomal dominant hereditary skin relaxation caused by FBLN5 gene mutation.

(2) Autosomal recessive dermatosis: The involved organs and severity of patients with autosomal recessive dermatosis are highly heterogeneous. The most common types are autosomal recessive skin laxity type I, autosomal recessive skin laxity type II (with developmental delay, microcephaly and skeletal abnormality) and autosomal recessive skin laxity type III (also known as Debarsi syndrome).

1.I autosomal recessive skin relaxation: I autosomal recessive skin relaxation is a special disease with typical severe emphysema and fatal vascular disease. Common system involvement includes atelectasis, emphysema, diverticulum of gastrointestinal tract and urogenital system, and vascular abnormalities (aneurysm, fibromuscular arterial dysplasia and stenosis). It may also be accompanied by skull abnormality, delayed fontanel closure, joint relaxation, dislocation of hip joint and inguinal hernia, but it is rare. Some scholars have detected mutations in FBLN5 and FBLN4 genes in some severe and fatal cases, but the genetic causes of most patients are still unclear.

2. Type II autosomal recessive skin relaxation: Type II autosomal recessive skin relaxation is a syndrome with developmental retardation, mental retardation and skeletal abnormality. Its typical manifestations are flabby skin and wrinkles all over the body, but the facial skin symptoms are mild, characterized by persistent wide fontanel, forehead bulge, slight skull cusp, inverted V-shaped eyebrows, drooping eyelids and dental caries, often accompanied by intrauterine growth retardation, dislocation of hip joint, chicken breast, scoliosis, inguinal hernia and flat feet. Kornak, Hucthagowder and others found that autosomal recessive cutaneous relaxation type II was caused by the mutation of ATP6V0A2 gene encoding V-ATPase subunit, and V-ATPase deficiency could lead to multiple system metabolic diseases through abnormal N- linked and O- linked glycosylation. Guernsey and Reversade detected the mutation of PYCR 1 gene in some patients with autosomal recessive skin relaxation type II, which can lead to the change of mitochondrial function and the aging of connective tissue, and then lead to premature aging in these patients.

3. Type III autosomal recessive skin relaxation: Type III autosomal recessive skin relaxation, also known as Debas syndrome, is characterized by premature aging such as thinning hair, abnormal cornea, intrauterine growth retardation and skin relaxation. When the patient was born, his skin was thin, translucent, wrinkled, inelastic and had obvious veins. The characteristic change of eyes is corneal opacity caused by the degradation of elastic fibers of corneal intestine membrane. Most patients have neurological and skeletal abnormalities at the same time, including impaired cognitive language function, dislocation of hip joint, high joint mobility, scoliosis and foot deformity. Many patients with Debarsi syndrome have overlapping features with autosomal recessive cutaneous relaxation type II. However, dystonia and progressive corneal abnormality highly suggest the diagnosis of De Barsy syndrome, and its pathological mechanism and genetic background are still unclear. Reversade and Lin reported that some patients with DeBarsy syndrome were associated with PYCR 1 gene mutation.

3.X-linked recessive hereditary skin relaxation: X-linked recessive hereditary skin relaxation is also called occipital angle syndrome.

Such patients have special manifestations at birth. In addition to extensive skin relaxation, the patient also has a typical face shape, including long person, hooked nose, high height, thin face and wide fontanel. The systems involved include chronic diarrhea, malabsorption, congenital hydronephrosis and urethral bladder diverticulum. Skeletal abnormalities include fontanel width and late closure, chicken breast, coxa valgus, short tubular bone, etc. Its diagnostic sign is angular exostosis on both sides of foramen magnum. Symptoms of cardiovascular system may also occur, including orthostatic hypotension, tortuous carotid artery and skin congestion. X-linked recessive cutaneous relaxation and Menkes's disease are diseases caused by mutation of the allele ATP7A encoding copper transporter. Severe ATP7A gene mutation leads to Menkes's disease, while mild ATP7A gene mutation leads to occipital angle syndrome.