Cutis laxa
Encyclopedia
Cutis laxa is a group of rare connective tissue disorders in which the skin
becomes inelastic and hangs loosely in folds.
In patients suffering from cutis laxa, mutations in the elastic fibers comprising the dermis
have been identified.
Cutis laxa may be caused by mutations in the genes: ELN
, ATP6V0A2
,
ATP7A
,FBLN4, FBLN5
, and PYCR1. A related neurocutaneous syndrome may be caused by mutations in the gene ALDH18A1 aka P5CS.
) because of lax ligament
s and tendon
s. When cutis laxa is severe, it can also affect the internal organs. The lung
s, heart
, intestine
s, or arteries
may be affected with a variety of severe impairments. In some cases, hernia
s and outpouching of the bladder can be observed.
Skin
-Dermis:The dermis is the layer of skin beneath the epidermis that consists of connective tissue and cushions the body from stress and strain. The dermis is tightly connected to the epidermis by a basement membrane. It also harbors many Mechanoreceptors that provide the sense of touch and heat...
becomes inelastic and hangs loosely in folds.
Causes
In most cases, cutis laxa is inherited. Autosomal dominant, autosomal recessive and X-linked recessive forms have been described, but acquired forms also occur.In patients suffering from cutis laxa, mutations in the elastic fibers comprising the dermis
Dermis
The dermis is a layer of skin between the epidermis and subcutaneous tissues, and is composed of two layers, the papillary and reticular dermis...
have been identified.
Cutis laxa may be caused by mutations in the genes: ELN
Elastin
Elastin is a protein in connective tissue that is elastic and allows many tissues in the body to resume their shape after stretching or contracting. Elastin helps skin to return to its original position when it is poked or pinched. Elastin is also an important load-bearing tissue in the bodies of...
, ATP6V0A2
ATP6V0A2
V-type proton ATPase 116 kDa subunit a isoform 2 also known as V-ATPase 116 kDa isoform a2 is an enzyme that in humans is encoded by the ATP6V0A2 gene.- Function :...
,
ATP7A
ATP7A
Copper-transporting ATPase 1 also known as copper pump 1 or Menkes disease-associated protein is a protein that in humans is encoded by the ATP7A gene.- Gene :...
,FBLN4, FBLN5
FBLN5
Fibulin-5 is a protein that in humans is encoded by the FBLN5 gene.-Clinical relevance:FBLN5 mutations have been described in patients with age-related macular degeneration, as well as being involved in Charcot-Marie-Tooth neuropathies....
, and PYCR1. A related neurocutaneous syndrome may be caused by mutations in the gene ALDH18A1 aka P5CS.
Presentation
It is characterized by skin that is loose, hanging, wrinkled, and lacking in elasticity. The loose skin is often most noticeable on the face, resulting in a prematurely aged appearance. The affected areas of skin may be thickened and dark. In addition, the joints are loose (hypermobilityHypermobility
Hypermobility describes joints that stretch farther than is normal. For example, some hypermobile people can bend their thumbs backwards to their wrists, bend their knee joints backwards, put their leg behind the head or other contortionist performances...
) because of lax ligament
Ligament
In anatomy, the term ligament is used to denote any of three types of structures. Most commonly, it refers to fibrous tissue that connects bones to other bones and is also known as articular ligament, articular larua, fibrous ligament, or true ligament.Ligament can also refer to:* Peritoneal...
s and tendon
Tendon
A tendon is a tough band of fibrous connective tissue that usually connects muscle to bone and is capable of withstanding tension. Tendons are similar to ligaments and fasciae as they are all made of collagen except that ligaments join one bone to another bone, and fasciae connect muscles to other...
s. When cutis laxa is severe, it can also affect the internal organs. The lung
Lung
The lung is the essential respiration organ in many air-breathing animals, including most tetrapods, a few fish and a few snails. In mammals and the more complex life forms, the two lungs are located near the backbone on either side of the heart...
s, heart
Heart
The heart is a myogenic muscular organ found in all animals with a circulatory system , that is responsible for pumping blood throughout the blood vessels by repeated, rhythmic contractions...
, intestine
Intestine
In human anatomy, the intestine is the segment of the alimentary canal extending from the pyloric sphincter of the stomach to the anus and, in humans and other mammals, consists of two segments, the small intestine and the large intestine...
s, or arteries
Artery
Arteries are blood vessels that carry blood away from the heart. This blood is normally oxygenated, exceptions made for the pulmonary and umbilical arteries....
may be affected with a variety of severe impairments. In some cases, hernia
Hernia
A hernia is the protrusion of an organ or the fascia of an organ through the wall of the cavity that normally contains it. A hiatal hernia occurs when the stomach protrudes into the mediastinum through the esophageal opening in the diaphragm....
s and outpouching of the bladder can be observed.
See also
- Ehlers-Danlos syndromeEhlers-Danlos syndromeEhlers–Danlos syndrome is a group of inherited connective tissue disorders, caused by a defect in the synthesis of collagen . The collagen in connective tissue helps tissues to resist deformation...
- Gerodermia osteodysplasticaGerodermia osteodysplasticaGerodermia osteodysplastica , also called geroderma osteodysplasticum and Walt Disney dwarfism, is a rare autosomal recessive connective tissue disorder included in the spectrum of cutis laxa syndromes....
- Occipital horn syndromeOccipital horn syndromeOccipital horn syndrome , formerly considered a variant of Ehlers-Danlos syndrome, is an X-linked recessive connective tissue disorder. It is caused by a deficiency in the transport of the essential mineral copper, associated with mutations in the ATP7A gene...
- List of cutaneous conditions