Acrodermatitis enteropathica
Encyclopedia
Acrodermatitis enteropathica is an autosomal
recessive metabolic disorder affecting the uptake of zinc
, characterized by periorificial (around the natural orifices) and acral (in the limbs) dermatitis
, alopecia
(loss of hair), and diarrhea
.
Similar features may be present in acquired zinc
deficiency. This disease also is related to deficiency of zinc due to congenital causes.
Other names for acrodermatitis enteropathica include:
tous, or may evolve further into crusted vesicles , bulla
s or pustules. The lesions are frequent around the mouth and anus
, and also in hands, feet and scalp
.
There may be suppurative inflammation
of the nail fold surrounding the nail plate
- known as paronychia
. Alopecia
- loss of hair from scalp, eyebrows and eyelashes may occur. The skin lesions may be secondarily infected by bacteria
such as Staphylococcus aureus
or fungi
like Candida albicans
. These skin lesions are accompanied by diarrhea.
A mutation
of the SLC39A4
gene on chromosome 8 q24.3
is responsible for the disorder. The SLC39A4 gene encodes a transmembrane protein
that serves as a zinc uptake protein. The features of the disease usually start manifesting as an infant is weaned from breast milk. This has led some scientists to suspect that human milk contains a beneficial substance that helps uptake of zinc and prevents the disease from being manifested while an infant is on breast milk.
supplementation in the range of greater than 1-2 mg/kg of bodyweight per day.
Autosome
An autosome is a chromosome that is not a sex chromosome, or allosome; that is to say, there is an equal number of copies of the chromosome in males and females. For example, in humans, there are 22 pairs of autosomes. In addition to autosomes, there are sex chromosomes, to be specific: X and Y...
recessive metabolic disorder affecting the uptake of zinc
Zinc
Zinc , or spelter , is a metallic chemical element; it has the symbol Zn and atomic number 30. It is the first element in group 12 of the periodic table. Zinc is, in some respects, chemically similar to magnesium, because its ion is of similar size and its only common oxidation state is +2...
, characterized by periorificial (around the natural orifices) and acral (in the limbs) dermatitis
Dermatitis
-Etymology:Dermatitis derives from Greek derma "skin" + -itis "inflammation" and genetic disorder.-Terminology:There are several different types of dermatitis. The different kinds usually have in common an allergic reaction to specific allergens. The term may describe eczema, which is also called...
, alopecia
Alopecia
Alopecia means loss of hair from the head or body. Alopecia can mean baldness, a term generally reserved for pattern alopecia or androgenic alopecia. Compulsive pulling of hair can also produce hair loss. Hairstyling routines such as tight ponytails or braids may induce Traction alopecia. Both...
(loss of hair), and diarrhea
Diarrhea
Diarrhea , also spelled diarrhoea, is the condition of having three or more loose or liquid bowel movements per day. It is a common cause of death in developing countries and the second most common cause of infant deaths worldwide. The loss of fluids through diarrhea can cause dehydration and...
.
Similar features may be present in acquired zinc
Zinc
Zinc , or spelter , is a metallic chemical element; it has the symbol Zn and atomic number 30. It is the first element in group 12 of the periodic table. Zinc is, in some respects, chemically similar to magnesium, because its ion is of similar size and its only common oxidation state is +2...
deficiency. This disease also is related to deficiency of zinc due to congenital causes.
Other names for acrodermatitis enteropathica include:
- Brandt syndrome
- Danbolt-Cross syndrome
- Congenital zinc deficiencyZinc deficiencyZinc deficiency is insufficient zinc to meet the needs of biological organisms. It can occur in both plants and animals. Zinc deficient soil is soil in which there is insufficient zinc to allow plants to grow normally.-Description:...
Signs and symptoms
Features of acrodermatitis enteropathica start appearing in the first few months of life, as the infant discontinues breast milk. There are erythematous patches and plaques of dry, scaly skin. The lesions may appear eczemaEczema
Eczema is a form of dermatitis, or inflammation of the epidermis . In England, an estimated 5.7 million or about one in every nine people have been diagnosed with the disease by a clinician at some point in their lives.The term eczema is broadly applied to a range of persistent skin conditions...
tous, or may evolve further into crusted vesicles , bulla
Blister
A blister is a small pocket of fluid within the upper layers of the skin, typically caused by forceful rubbing , burning, freezing, chemical exposure or infection. Most blisters are filled with a clear fluid called serum or plasma...
s or pustules. The lesions are frequent around the mouth and anus
Anus
The anus is an opening at the opposite end of an animal's digestive tract from the mouth. Its function is to control the expulsion of feces, unwanted semi-solid matter produced during digestion, which, depending on the type of animal, may be one or more of: matter which the animal cannot digest,...
, and also in hands, feet and scalp
Scalp
The scalp is the anatomical area bordered by the face anteriorly and the neck to the sides and posteriorly.-Layers:It is usually described as having five layers, which can conveniently be remembered as a mnemonic:...
.
There may be suppurative inflammation
Inflammation
Inflammation is part of the complex biological response of vascular tissues to harmful stimuli, such as pathogens, damaged cells, or irritants. Inflammation is a protective attempt by the organism to remove the injurious stimuli and to initiate the healing process...
of the nail fold surrounding the nail plate
Nail plate
The nail plate is the hard and translucent portion of the nail, composed of keratin.- See also :* Runner's toe, repetitive injury seen in runners...
- known as paronychia
Paronychia
The nail disease paronychia , commonly misidentified as a synonym for whitlow or felon, is an often-tender bacterial or fungal hand infection or foot infection where the nail and skin meet at the side or the base of a finger or toenail...
. Alopecia
Alopecia
Alopecia means loss of hair from the head or body. Alopecia can mean baldness, a term generally reserved for pattern alopecia or androgenic alopecia. Compulsive pulling of hair can also produce hair loss. Hairstyling routines such as tight ponytails or braids may induce Traction alopecia. Both...
- loss of hair from scalp, eyebrows and eyelashes may occur. The skin lesions may be secondarily infected by bacteria
Bacteria
Bacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...
such as Staphylococcus aureus
Staphylococcus aureus
Staphylococcus aureus is a facultative anaerobic Gram-positive coccal bacterium. It is frequently found as part of the normal skin flora on the skin and nasal passages. It is estimated that 20% of the human population are long-term carriers of S. aureus. S. aureus is the most common species of...
or fungi
Fungus
A fungus is a member of a large group of eukaryotic organisms that includes microorganisms such as yeasts and molds , as well as the more familiar mushrooms. These organisms are classified as a kingdom, Fungi, which is separate from plants, animals, and bacteria...
like Candida albicans
Candida albicans
Candida albicans is a diploid fungus that grows both as yeast and filamentous cells and a causal agent of opportunistic oral and genital infections in humans. Systemic fungal infections including those by C...
. These skin lesions are accompanied by diarrhea.
Genetics
Mutation
In molecular biology and genetics, mutations are changes in a genomic sequence: the DNA sequence of a cell's genome or the DNA or RNA sequence of a virus. They can be defined as sudden and spontaneous changes in the cell. Mutations are caused by radiation, viruses, transposons and mutagenic...
of the SLC39A4
SLC39A4
SLC39A4 is a transmembrane protein associated with acrodermatitis enteropathica.-External links:*...
gene on chromosome 8 q24.3
Locus (genetics)
In the fields of genetics and genetic computation, a locus is the specific location of a gene or DNA sequence on a chromosome. A variant of the DNA sequence at a given locus is called an allele. The ordered list of loci known for a particular genome is called a genetic map...
is responsible for the disorder. The SLC39A4 gene encodes a transmembrane protein
Transmembrane protein
A transmembrane protein is a protein that goes from one side of a membrane through to the other side of the membrane. Many TPs function as gateways or "loading docks" to deny or permit the transport of specific substances across the biological membrane, to get into the cell, or out of the cell as...
that serves as a zinc uptake protein. The features of the disease usually start manifesting as an infant is weaned from breast milk. This has led some scientists to suspect that human milk contains a beneficial substance that helps uptake of zinc and prevents the disease from being manifested while an infant is on breast milk.
Treatment
Without treatment, the disease is fatal and affected individuals may die within a few years. There is no cure for the condition. Treatment includes lifelong dietary zincZinc
Zinc , or spelter , is a metallic chemical element; it has the symbol Zn and atomic number 30. It is the first element in group 12 of the periodic table. Zinc is, in some respects, chemically similar to magnesium, because its ion is of similar size and its only common oxidation state is +2...
supplementation in the range of greater than 1-2 mg/kg of bodyweight per day.