About doc 16 (unilateral hemidysplasia type)

What is doc 16 (unilateral hemidysplasia type)?

CHILD syndrome (an acronym for congenital hemidysplasia with ichthyosiform erythroderma and limb defects) is an inherited disorder, affecting primarily women, that is characterized by ichthyosis-like skin abnormalities and limb defects on one side of the body. Other abnormalities may be present, as well.

If defects of other body organs are present, they are usually on the same side of the body as the skin and limb abnormalities.



What are the symptoms for doc 16 (unilateral hemidysplasia type)?

Vertebrae symptom was found in the doc 16 (unilateral hemidysplasia type) condition

CHILD syndrome is usually present at birth. It may first become apparent at some point during the first month of life.

The skin is usually dry, itchy, red and scaly (ichthyosiform erythroderma) on one side of the body, although minor skin involvement in the shape of lines or segments may occur on the opposite side of the body. Bands of normal skin may be found on the affected side as well. Patients with CHILD syndrome may be bald on one side of the head and have clawlike nails.

Limb defects usually occur on the same side of the body as the major skin symptoms. These defects may range from underdevelopment of fingers and toes to complete absence of a limb. Some of the types of skeletal defects that might occur include abnormal ribs, anomalies of the shoulder blades (scapula), webbing of the skin between joints, and absence of muscles of the breast (pectoral).

Heart defects sometimes associated with this syndrome include defects in the walls between auricles and/or ventricles, as well as complex heart disease in which less than adequate amounts of oxygen get to the organ (cyanosis).

Abnormalities of the central nervous system, blood vessels, kidneys, thyroid, lungs and adrenal glands, and of the reproductive and urinary system, may also occur. Most of these abnormalities result from underdevelopment of the affected side of the body.



What are the causes for doc 16 (unilateral hemidysplasia type)?

CHILD syndrome is a hereditary disorder transmitted as an X-linked dominant trait. The faulty gene is on the long arm of the X chromosome (Xq28). The protein/enzyme product coded by the gene has been identified as NSDHL and governs an essential step in the biosynthesis of cholesterol.

Chromosomes, which are present in the nucleus of human cells, carry the genetic information for each individual. Human body cells normally have 46 chromosomes. Pairs of human chromosomes are numbered from 1 through 22 and the sex chromosomes are designated X and Y. Males have one X and one Y chromosome and females have two X chromosomes. Each chromosome has a short arm designated “p” and a long arm designated “q”. Chromosomes are further sub-divided into many bands that are numbered. For example, “chromosome Xq28” refers to band 28 on the long arm of the X-chromosome. The numbered bands specify the location of the thousands of genes that are present on each chromosome.

Genetic diseases are determined by the combination of genes for a particular trait which are on the chromosomes received from the father and the mother.

Dominant genetic disorders occur when only a single copy of an abnormal gene is necessary for the appearance of the disease. The abnormal gene can be inherited from either parent, or can be the result of a new mutation (gene change) in the affected individual. The risk of passing the abnormal gene from affected parent to offspring is 50% for each pregnancy regardless of the sex of the resulting child.

X-linked dominant disorders are caused by an abnormal gene on the X chromosome, but in these rare conditions, females with an abnormal gene are affected with the disease. Males with an abnormal gene are more severely affected than females, and many of these males do not survive.



What are the treatments for doc 16 (unilateral hemidysplasia type)?

Skin (dermatologic) symptoms of CHILD syndrome are treated by applying skin softening (emollient) ointments, preferably plain petroleum jelly. This can be especially effective after bathing while the skin is still moist. Salicylic acid gel is another particularly effective ointment. The skin should be covered at night with an airtight, waterproof dressing when this ointment is used. Lactate lotion can also be an effective treatment for the skin symptoms of this disorder.

Drugs derived from Vitamin A (retinoids) such as tretinoin, motretinide, and etretinate can be effective against dermatologic symptoms of CHILD syndrome. but can cause toxic effects on the bones in some cases. A synthetic derivative of Vitamin A, isotretinoin (accutane), when taken by pregnant women, can cause severe birth defects to the fetus. These Vitamin A compounds have not yet been approved by the Food and Drug Administration (FDA) for treatment of Ichthyosis.

Other treatment is symptomatic and supportive. Genetic counseling may be helpful to families of patients with CHILD syndrome.



What are the risk factors for doc 16 (unilateral hemidysplasia type)?

Unilateral hemidysplasia or the CHILD syndrome as the name suggests, affects one side of the body. Predominantly, it affects the right side as twice as it affects the left side.

Risk factors

  • This condition has an X-linked dominant pattern of inheritance.
  • CHILD syndrome follows an X-linked mode of inheritance. Hence, males are at a higher risk of inheritance than females. Because males receive one X-chromosome, whereas females receive two. Due to the absence of a double allele, the mutant expresses the respective phenotype. Whereas in females, the mutant can be present in a heterozygous state that causes a less severe form of the disease.
  • Most cases of CHILD syndrome occur sporadically(only one family member is affected). The condition can run in families rarely.
  • For female individuals, the risk of inheritance is the highest when both parents are affected.
  • For males, the carrier or affected mother is the only risk of inheritance.
  • The other risk factors include prolonged exposure to sunlight, heat, and friction that worsen the symptoms.


Symptoms
Patches of red and inflamed skin and flaky scales,Unilateral underdevelopment of ribs, neck, vertebrae, etc.,Short limbs or digits or the digits might even be missing
Conditions
Psoriasiform epidermis with hyperkeratosis and parakeratosis,Unilateral ptychotropism,Verruciform xanthomas,Scaling alopecia,Ichthyosiform erythroderma,Hyperkeratosis,Skeletomuscular abnormalities ranging from hypoplasia to agenesis
Drugs
Softening agents including Petrolatum, dimethicone, and propylene glycol,Topical or systemic retinoids including acitretin, alitretinoin, isotretinoin, and etretinate, 2% cholesterol and 2% lavostatin, or 2% simvastatin



Is there a cure/medications for doc 16 (unilateral hemidysplasia type)?

Dermatologic symptoms of Unilateral hemidysplasia or the CHILD syndrome are generally treated by applying skin softening (emollient) ointments like plain petroleum jelly.

Cure/medications:

  • Application of skin softeners(emollients) after bathing. A salicylic acid gel is the most effective emollient. Other softening agents include Petrolatum, dimethicone, and propylene glycol.
  • Topical or systemic retinoids include acitretin, alitretinoin, isotretinoin, and etretinate.
  • Lactate lotion can also be an effective treatment for skin symptoms. 12 % lactic acid creams and lotions help reduce itching
  • Urea is effective against dryness.
  • 2% cholesterol and 2% lovastatin treat ichthyosis. 2% simvastatin is an alternative to lovastatin.
  • Vitamin A (retinoids) such as tretinoin, motretinide, and etretinate can be effective against dermatologic symptoms of the syndrome.
  • Surgical interventions: Surgical excision of lesions is an option when the lesions grow severely. Dermabrasion followed by split-thickness skin grafting can successfully treat skin anomalies.
  • Surgeries may also be performed for the organ systems like lung, heart, and renal anomalies involved. Orthopedic abnormalities can be treated with braces or corrective surgery.
  • Genetic counseling may be helpful to families of patients with CHILD syndrome.


Symptoms
Patches of red and inflamed skin and flaky scales,Unilateral underdevelopment of ribs, neck, vertebrae, etc.,Short limbs or digits or the digits might even be missing
Conditions
Psoriasiform epidermis with hyperkeratosis and parakeratosis,Unilateral ptychotropism,Verruciform xanthomas,Scaling alopecia,Ichthyosiform erythroderma,Hyperkeratosis,Skeletomuscular abnormalities ranging from hypoplasia to agenesis
Drugs
Softening agents including Petrolatum, dimethicone, and propylene glycol,Topical or systemic retinoids including acitretin, alitretinoin, isotretinoin, and etretinate, 2% cholesterol and 2% lavostatin, or 2% simvastatin



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