Keloid, also known as keloid disorder and keloidal scar,
is the formation of a type of scar which, depending on its maturity, is composed mainly of either type III (early) or type I (late) collagen. It is a result of an overgrowth of granulation tissue (collagen type 3) at the site of a healed skin injury which is then slowly replaced by collagen type 1. Keloids are firm, rubbery lesions or shiny, fibrous nodules, and can vary from pink to the color of the persons skin or red to dark brown in color. A keloid scar is benign and not contagious, but sometimes accompanied by severe itchiness, pain, and changes in texture. In severe cases, it can affect movement of skin. Worldwide, men and women of African, Asian, Hispanic and European descent can develop these raised scars. In the United States keloid scars are seen 15 times more frequently in people of sub-Saharan African descent than in people of European descent. There is a higher tendency to develop a keloid among those with a family history of keloids and people between the ages of 10 and 30 years. Keloids should not be confused with hypertrophic scars, which are raised scars that do not grow beyond the boundaries of the original wound. Signs and symptoms
Keloids expand in claw-like growths over normal skin. They have the capability to hurt with a needle-like pain or to itch, the degree of sensation varying from person to person.Keloids form within scar tissue.
Renpennings syndrome is a neurodevelopmental disorder recognised in males that causes intellectual disability, mild growth retardation with examples in the testes and head, and a somewhat short stature. The condition only affects males, starting at birth. Presentation
People with Renpennings typically begin learning language at an ordinary pace, but by the age of 3–4 they experience a regression in mental and physical development, such as mild low muscle tone resulting in elongated faces and rapid loss in the normal growth of the head (microcephaly). Small testes and short stature are also known to commonly occur. Genetics
It is associated with mutations in the PQBP1 gene. The gene product is a polyglutamine-binding protein involved in transcription and pre-mRNA splicing. The gene itself is located on the short arm of the X chromosome (Xp11.23). The most common mutations causing this condition occur in exon 4. Diagnosis
This diagnosis may be suspected on clinical grounds but should be confirmed by sequencing the PQBP1 gene. Treatment
There is no specific or curative treatment for this condition at present. Management is supportive

Epidemiology
This condition normally only occurs in males but a case in a female has been reported. History
This condition was first characterized in 1962. and later described by Hans Renpenning in 1963 after he documented these traits on many children in one family alone. See also
Lujan-Fryns syndrome
Fragile x syndrome

References


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