About zinc deficiency, congenital
What is zinc deficiency, congenital?
Acrodermatitis enteropathica (AE) is a disorder of zinc metabolism that occurs in one of two forms: an inborn (congenital) form and an acquired form. The inborn form of AE is a rare genetic disorder characterized by intestinal abnormalities that lead to the inability to absorb zinc from the intestine. The lack of zinc presents, characteristically, as: (1) skin inflammation with pimples (pustular dermatitis) occurring around the mouth and/or anus, (2) diarrhea, and (3) abnormal nails (nail dystrophy). In the acute phase, irritability and emotional disturbances are evident due to wasting (atrophy) of the brain cortex. It is important to recognize and treat this disorder.
The acquired form of this disorder generates similar symptoms. Acquired AE sometimes results from special intravenous nutritional programs that are prepared without the appropriate amount of zinc.
Supplemental zinc usually eliminates the symptoms.
What are the symptoms for zinc deficiency, congenital?
Acrodermatitis enteropathica is characterized by chronic Diarrhea which may be mild or severe, and the presence of fatty substances in the feces (steatorrhea). In the congenital form symptoms start gradually, frequently at the time of weaning of an infant. The skin around body openings such as the mouth, anus, and eyes, and the skin on elbows, knees, hands, and feet become inflamed. Skin lesions are usually blistered (vesicobullous) and after drying out become psoriasis-like. The skin around the nails may also be inflamed and the nail may be abnormal due to malnourished tissue. Hair loss on the scalp, eyelids, and eyebrows may be total (alopecia). Inflammation of the membrane that lines the eyelid (conjunctivitis), usually also occurs.
The blood zinc level in people with the congenital form of this disorder is abnormally low, although rarely normal blood zinc levels have also been observed.
A separate type of transient zinc deficiency in infants can result from a different congenital abnormality – but one which is not in the infant but rather in the mother. Notably in some lactating women, a zinc-binding factor produced by the pancreas and present in human milk may be lacking. Breast-fed infants of these women may also develop lowered blood levels of zinc with other symptoms of this disorder, because the milk is deficient in the proper amount of the zinc- binding factor. Once an alternative source of oral zinc is introduced into the infant’s diet (e.g. formula milk) the zinc deficiency rectifies and the infant is cured.
With treatment, all patients with acrodermatitis enteropathica can lead normal lives.
Frequently, long remissions may occur, usually starting during puberty. However, in rare cases, women may have a recurrence of the disorder during pregnancy and increased zinc supplementation may be necessary.
What are the causes for zinc deficiency, congenital?
The congenital form of acrodermatitis enteropathica is transmitted as an autosomal recessive genetic disorder. It appears to be the result of mutations in the SLC39A4 gene.
Genetic diseases are determined by a combination of genes for a particular trait that are on the chromosomes received from the father and the mother.
Recessive genetic disorders occur when an individual inherits the same abnormal gene for the same trait from each parent. If an individual receives one normal gene and one gene for the disease, the person will be a carrier for the disease, but usually will not show symptoms. The risk for two carrier parents to both pass the defective gene and, therefore, have an affected child is 25% with each pregnancy. The risk to have a child who is a carrier like the parents is 50% with each pregnancy. The chance for a child to receive normal genes from both parents and be genetically normal for that particular trait is 25%. The risk is the same for males and females.
All individuals carry a few abnormal genes. Parents who are close relatives (consanguineous) have a higher chance than unrelated parents to both carry the same abnormal gene, which increases the risk to have children with a recessive genetic disorder.
Some women fail to generate adequate zinc levels in their breast milk – and that can also have a genetic cause. A single mutation in the SLC30A2 mutation can reduce breast milk zinc. This tendency does not require two gene abnormalities, one is sufficient and people who have this condition have a 50% chance of passing it on to their offspring.
What are the treatments for zinc deficiency, congenital?
Acrodermatitis enteropathica is treated with zinc supplements in the form of zinc sulfate. These supplements should be given as soon as diagnosis of the disorder is made and they have to be continued for life. The drug Diodoquin (iodoquinol) is another treatment that usually clears up symptoms within a week. If the disorder is caused by intravenous feeding, adding zinc supplements to the nutritional regimen can prevent and/or clear up manifestations of AE.
Genetic counseling is recommended for families of patients with the congenital form of acrodermatitis enteropathica.
What are the risk factors for zinc deficiency, congenital?
Congenital zinc deficiency is an inborn error mechanism in thezinc availability in the body. Although dietary variables are frequently the cause of zinc deficiency, various genetic abnormalities of zinc insufficiency have been reported. The most frequently reported inherited human ailment is acrodermatitis enteropathica. In several of the few cases that have been reported, this disorder is associated with mutations in the hZIP4 gene, a member of the SLC39 family, whose members encode membranebound putative zinc transporters Risk factors- The congenital form of arodermatitis enteropathica or zinc deficiency is a rare disorder beginning during infancy. The incidence is about 1 in 500,000 births and the condition affects males and females in equal numbers. Sinc e the disease is recessive condition it is usually seen when both the parents present with mutated gene- consanguineous marriage is an associated risk factor. Healthy breast-fed infants of female patients with the disorder can also become affected. The acquired form of AE is rare because in recent years zinc supplements have been added to the parenteral nutrition regimen, although acquired forms are more common in some regions such as Southeast Asia and sub-Saharan Africa where gastro-intestinal malabsorption syndrome are more frequent. This disease can affect men and women equally. Commonly observed in the regions with low dietary intake of zinc.
Is there a cure/medications for zinc deficiency, congenital?
Congenital zinc deficiency is an inborn error mechanism in the zinc availability in the body. Although dietary variables are frequently the cause of zinc deficiency, various genetic abnormalities of zinc insufficiency have been reported. The most frequently reported inherited human ailment is acrodermatitis enteropathica. In several of the few cases that have been reported, this disorder is associated with mutations in the hZIP4 gene, a member of the SLC39 family, whose members encode membrane bound putative zinc transporters Risk factors- The congenital form of arodermatitis enteropathica or zinc deficiency is a rare disorder beginning during infancy. The incidence is about 1 in 500,000 births and the condition affects males and females in equal numbers. Since the disease is recessive condition it is usually seen when both the parents present with mutated gene- consanguineous marriage is an associated risk factor. Treatment- Zinc dietary supplements in the form of zinc sulphate are used to treat acrodermatitis enteropathica. These supplements must be taken for the rest of one's life and should be started as soon as the disease is diagnosed. Another treatment that typically eliminates symptoms in a week is the medication Diodoquin (iodoquinol). If intravenous feeding is the root cause of the disease, supplementing the diet with zinc can help to prevent and/or treat AE symptoms. Treatment of acrodermatitis enteropathica begins with high-dose supplementation using oral elemental zinc at 3 mg/kg/day Zinc can be given during pregnancy. Normal doses of zinc are generally well tolerated but overdose may cause toxicity.