Talk:Integumentary System - Abnormalities

Introduction

This page lists a few of the abnormalities associated with the Integumentary system. As there are many different specicializations associated with this system and therefore many very specific defects, only a few are included here.

For a more detailed list of Integumentary Defects search the OMIM or PubMed Databases.

Ehlers-Danlos Syndrome

The main features of classic Ehlers-Danlos syndrome, which includes EDS I and EDS II, are loose-jointedness and fragile, bruisable skin that heals with peculiar scars. The syndrome is caused by mutation in the collagen gene. Infants are born prematurely due to premature rupture of fetal membranes.

OMIM Database Search: "Ehlers-Danlos Syndrome" (2005 - 77 search results)

References:

GeneReviews Ehlers-Danlos Syndrome | Ehlers-Danlos Syndrome, Vascular Type | Ehlers-Danlos Syndrome, Kyphoscoliotic Form

Epidermolysis Bullosa Simplex

An autosomal dominant disease of keratin, generating skin fagility and non-scarring blisters of the skin caused by little or no trauma.

Four clinical subtypes: 1. EBS - Weber-Cockayne - mild blistering of the hands and feet 2. EBS - Koebner, 3. EBS - mottled pigmentation, 4. EBS - Dowling-Meara - generalized blistering which can be fatal.

OMIM Database Search: "Epidermolysis Bullosa Simplex" (2005 - 35 search results)

References:

GeneReviews Epidermolysis Bullosa Simplex

Autosomal Recessive Congenital Ichthyosis

Ichthyosis is an excessive keratinization disorder.

OMIM Database Search: "Congenital Ichthyosis" (2005 - 73 search results)

References:

GeneReviews Autosomal Recessive Congenital Ichthyosis

Cutis Aplasia

Congenital absence of the skin, particularly on the scalp, larger defects may extend to the dura or meninges. Generally isolated lesions, but can also be associated with a variety of other genetic disorders. Heals as a flat scar or keloid lump.

File:CutisAplasia.jpg

Cutis Aplasia (Image: NZ Crown copyright)

File:CutisAplasiaKeloid.jpg

Cutis Aplasia Keloid (Image: NZ Crown copyright)

OMIM Database Search: "Cutis Aplasia" (2006 - 33 search results)

References:

Incontinentia Pigmenti

"An X-linked dominant disorder with most but not all cases affecting females. The skin changes follow characteristic four stages. In the neonatal period the first stage is noted with blisters often preceded or accompanied by erythema. These involve any part of the body but usually not the face. They do not cross the midline. These lesions are best seen in the second photograph in the groin and suprapubic region. The lesions follow a linear distribution in the limbs and circumferentially around the trunk. Crops of lesions may occur over a period of weeks to few months. During that stage, peripheral eosinophilia may be noted. The second stage follows and is characterised by hyperkeratosis or verrucous changes. At times the 2 stages occur simultaneously as noted in the first and third photograph. The third stage is that of hyperpigmentation typically appearing as streaks or whorls. It may be present throughout childhood. The fourth stage seen in teenage or adults is that of pale or atrophic streaks. In the neonatal period, IP must be differentiated from herpetic lesions, bullous impetigo and epidermolysis bullosa." (Text and Images: NZ Crown copyright)

OMIM Database Search: "Incontinentia Pigmenti" (2006 - 26 search results)

References:

Neuroblastoma

(More? [../ncrest2.htm Neural Crest - Abnormalities])

OMIM Database Search: "Neuroblastoma" (2006 - 242 search results)

References:

Teeth Defects

amelogenesis imperfecta hypocalcification leads to soft enamal on teeth. Yellow dentine is visible through the thin layer of enamal.

dentinogenesis imperfecta odontoblasts fail to differentiate. Enamal of teeth wears excessively.

enamel hypoplasia environmental factors affecting ameloblast formation of enamal on teeth.

OMIM Database Search: "amelogenesis imperfecta" (2005 - 30 search results) | "dentinogenesis imperfecta" (2005 - 29 search results) | "enamel hypoplasia" (2005 - 53 search results) |

Mammary Glands

Gynecomastia is stimulation by maternal sex hormones leads to excessive development of newborn male mammary glands. There are several possible causes of this excess estrogen in boys which also causes musculoskeletal abnormalities (premature growth spurt, early fusion of epiphyses, and decreased adult height).

OMIM Database Search: "Gynecomastia" (2005 - 44 search results)

Breast Cancer

In 1994, two breast cancer susceptibility genes were identified

BRCA1 on chromosome 17
BRCA2 on chromosome 13

When an individual carries a mutation in either BRCA1 or BRCA2, they are at an increased risk of being diagnosed with breast or ovarian cancer at some point in their lives. Normal function of these genes was to participate in repairing radiation-induced breaks in double-stranded DNA. It is though that mutations in BRCA1 or BRCA2 might disable this mechanism, leading to more errors in DNA replication and ultimately to cancerous growth.

Breast Cancer Detection reduce mortality is through early detection (general screening of the population for BRCA1 and BRCA2 is not yet recommended). New strategies to find anti-cancer drugs are constantly being developed. The latest, called 'synthetic lethal screening' looks for new drug targets in organisms such as yeast and fruit flies. In the same way that studies in yeast recently helped to identify the functions of BRCA1 and BRCA2, it is thought that drugs that work in more primative organisms will also be applicable to humans.

Vascular Abnormalities

Angiomas are vascular disorder resulting in excessive skin vascularisation.

OMIM Database Search: "Angioma" (2005 - 23 search results)

Skin Colour Abnormalities

There are many different factors that can affect skin colouration, some are genetically related while others are due to diet or pharmacological drug side effects.

Albinism autosomal recessive trait resulting in lack of pigment in skin, hair and retina.

Jaundice is the yellow color of skin (and mucous membranes) and is not an abnormality of the skin and is often seen in newborn infants. It is due to accumulation of bile pigments in blood and their deposition in body tissues.

Carotenemia excess carotene intake results from eating large quantities of green and yellow vegetables, tomatoes, or yellow corn.

Quinacrine used for treatment of giardiasis, produces a yellow skin color, but the urine remains normal.

OMIM Database Search: "albinism" (2005 - 73 search results) | "Jaundice" (2005 - 121 search results)