Ehlers–Danlos syndromes (EDS) are a group of 13 genetic connective-tissue disorders. Symptoms often include loose joints, joint pain, stretchy velvety skin, and abnormal scar formation. These may be noticed at birth or in early childhood. Complications may include aortic dissection, joint dislocations, scoliosis, chronic pain, or early osteoarthritis. The current classification was last updated in 2017, when a number of rarer forms of EDS were added.
Progeria is a specific type of progeroid syndrome, also known as Hutchinson–Gilford syndrome or Hutchinson–Gilford progeroid syndrome (HGPS). A single gene mutation is responsible for causing progeria. The affected gene, known as lamin A (LMNA), makes a protein necessary for holding the nucleus of the cell together. When this gene gets mutated, an abnormal form of lamin A protein called progerin is produced. Progeroid syndromes are a group of diseases that cause individuals to age faster than usual, leading to them appearing older than they actually are. People born with progeria typically live until their mid to late teens or early twenties.
Darier's disease (DD) is a rare, genetic skin disorder. It is an autosomal dominant disorder, that is, if one parent has DD, there is a 50% chance than a child will inherit DD. It was first reported by French dermatologist Ferdinand-Jean Darier in 1889.
Urticaria pigmentosa (also known as generalized eruption of cutaneous mastocytosis (childhood type) ) is the most common form of cutaneous mastocytosis. It is a rare disease caused by excessive numbers of mast cells in the skin that produce hives or lesions on the skin when irritated.
Livedo reticularis is a common skin finding consisting of a mottled reticulated vascular pattern that appears as a lace-like purplish discoloration of the skin. The discoloration is caused by reduction in blood flow through the arterioles that supply the cutaneous capillaries, resulting in deoxygenated blood showing as blue discoloration. This can be a secondary effect of a condition that increases a person's risk of forming blood clots, including a wide array of pathological and nonpathological conditions. Examples include hyperlipidemia, microvascular hematological or anemia states, nutritional deficiencies, hyper- and autoimmune diseases, and drugs/toxins.
Ectrodactyly–ectodermal dysplasia–cleft syndrome, or EEC, and also referred to as EEC syndrome and split hand–split foot–ectodermal dysplasia–cleft syndrome is a rare form of ectodermal dysplasia, an autosomal dominant disorder inherited as a genetic trait. EEC is characterized by the triad of ectrodactyly, ectodermal dysplasia, and facial clefts. Other features noted in association with EEC include vesicoureteral reflux, recurrent urinary tract infections, obstruction of the nasolacrimal duct, decreased pigmentation of the hair and skin, missing or abnormal teeth, enamel hypoplasia, absent punctae in the lower eyelids, photophobia, occasional cognitive impairment and kidney anomalies, and conductive hearing loss.
Loeys–Dietz syndrome (LDS) is an autosomal dominant genetic connective tissue disorder. It has features similar to Marfan syndrome and Ehlers–Danlos syndrome. The disorder is marked by aneurysms in the aorta, often in children, and the aorta may also undergo sudden dissection in the weakened layers of the wall of the aorta. Aneurysms and dissections also can occur in arteries other than the aorta. Because aneurysms in children tend to rupture early, children are at greater risk for dying if the syndrome is not identified. Surgery to repair aortic aneurysms is essential for treatment.
Conradi–Hünermann syndrome is a rare type of chondrodysplasia punctata. It is associated with the EBP gene and affects between one in 100,000 and one in 200,000 babies.
Sack–Barabas syndrome is an older name for the medical condition vascular Ehlers–Danlos syndrome (vEDS). It affects the body's blood vessels and organs, making them prone to rupture.
Type III Collagen is a homotrimer, or a protein composed of three identical peptide chains (monomers), each called an alpha 1 chain of type III collagen. Formally, the monomers are called collagen type III, alpha-1 chain and in humans are encoded by the COL3A1 gene. Type III collagen is one of the fibrillar collagens whose proteins have a long, inflexible, triple-helical domain.
Prelamin-A/C, or lamin A/C is a protein that in humans is encoded by the LMNA gene. Lamin A/C belongs to the lamin family of proteins.
Netherton syndrome is a severe, autosomal recessive form of ichthyosis associated with mutations in the SPINK5 gene. It is named after Earl W. Netherton (1910–1985), an American dermatologist who discovered it in 1958.
Progerin is a truncated version of the lamin A protein involved in the pathology of Hutchinson–Gilford progeria syndrome. Progerin is most often generated by a sporadic single point nucleotide polymorphism c.1824 C>T in the gene that codes for matured Lamin A. This mutation activates a cryptic splice site that induces a larger mutation in the processed prelamin A messenger RNA, causing the deletion of a 50 amino-acid group near the C-terminus of the prelamin A protein. The endopeptidase ZMPSTE24 cannot cleave between the missing RSY - LLG amino acid sequence during the maturation of Lamin A, due to the deletion of the 50 amino acids which included that sequence. This leaves the intact premature Lamin A bonded to the methylated carboxyl farnesyl group creating the defective protein Progerin, rather than the desired protein matured Lamin A. Approximately 90% of all Hutchinson–Gilford progeria syndrome cases are heterozygous for this deleterious single nucleotide polymorphism within exon 11 of the LMNA gene causing the post-translational modifications to produce progerin.
Gerodermia osteodysplastica (GO) is a rare autosomal recessive connective tissue disorder included in the spectrum of cutis laxa syndromes.
Chilblain lupus erythematosus was initially described by Hutchinson in 1888 as an uncommon manifestation of chronic cutaneous lupus erythematosus. Chilblain lupus erythematosus is characterized by a rash that primarily affects acral surfaces that are frequently exposed to cold temperatures, such as the toes, fingers, ears, and nose. The rash is defined by oedematous skin, nodules, and tender plaques with a purple discoloration.
Howel–Evans syndrome is an extremely rare condition involving thickening of the skin in the palms of the hands and the soles of the feet (hyperkeratosis). This familial disease is associated with a high lifetime risk of esophageal cancer. For this reason, it is sometimes known as tylosis with oesophageal cancer (TOC).
Ichthyosis prematurity syndrome (IPS) is a dermatological disease with known genetic causes. This syndrome is a rare subcategory of autosomal recessive congenital ichthyosis (ARCI). It is associated with complications in the mid-trimester of a pregnancy leading to premature births. Although most prevalent in individuals of Scandinavian origin, there have also been scattered cases in people of Japanese, Italian and Indian ethnicity. This disorder is also referred to as ichthyosis congenital type IV.
Microphthalmia–dermal aplasia–sclerocornea syndrome is a condition characterized by linear skin lesions. MLS is a rare X-linked dominant male-lethal disease characterized by unilateral or bilateral microphthalmia and linear skin defects in affected females, and in utero lethality for affected males. It can be associated with HCCS, mutations in it cause microphthalmia with Linear Skin Defects Syndrome.
Progeroid syndromes (PS) are a group of rare genetic disorders that mimic physiological aging, making affected individuals appear to be older than they are. The term progeroid syndrome does not necessarily imply progeria, which is a specific type of progeroid syndrome.
