CHILD syndrome is a disorder seen almost always in women, in which one side of the body is affected by hemidysplasia. The skin on the ipsilateral side shows patches of ichthyosiform erythroderma. In two-thirds of all cases, it is the right side which is defective.
The condition is present at birth and becomes obvious within the first month of life, persisting throughout life. It is a rare disease, with only approximately 60 cases being reported to date. Of these, only one was male.
The cause of the syndrome is a somatic mutation in the NSHDL gene. This is concerned with cholesterol synthesis. When it is turned off, cholesterol levels are lowered and possibly toxins build up within cells, though the exact pathophysiology is not yet clear. It is X-linked, which accounts for its being an exclusively female disease. The mutation in the single X chromosome is presumably fatal to the developing male embryo. Most cases are sporadic and therefore do not run in families.
Associated findings may include skeletal, neurological, and visceral anomalies, all on the same side as the cutaneous lesions. The term CHILD itself stands for Congenital Hemidysplasia with Icthyosiform nevus and Limb Defects.
The patient with CHILD syndrome has ichthyosiform erythroderma, which refers to skin lesions that are dry, inflamed, and scaly, and are especially located along the skin folds and creases. They are covered with a waxy layer. Loss of hair and nails which are long and curved, rather like claws, may also occur.
The extent of dysplasia may range from mild skeletal hypoplasia to complete aplasia of a limb. Spinal scoliosis, hemihypoatrophy of the face and short stature, may all be seen. Chondrodysplasia punctate can also be a feature in some infants.
In many patients with CHILD syndrome, one of the two cerebral hemispheres may be missing or hypoplastic, or one side may be paralyzed, with or without cranial nerves palsies. Hearing and sensory loss are also common.
CHILD syndrome may be associated with congenital defects of the heart and blood vessels, including atrial or ventricular septal defects or complex congenital heart defects. Another type of visceral defect refers to renal or pulmonary agenesis or hypoplasia.
Diagnosis and Management
Most cases are diagnosed by physical examination. The application of emollient ointments is essential to keep the skin as soft as possible, which alleviates the cracking and scaling of the lesions. Salicylic acid is also an effective preparation, applied at night under an occlusive dressing. Lactate lotion is a third option for skin symptoms.
Vitamin A derivatives including retinoids, tretinoin, and etretinate are useful in controlling rapid proliferation of epithelial cells and promoting healing of epithelial breakdown. However, they may produce bone damage in some cases. Accutane, which is the trade name for isotretinoin, is highly teratogenic and can be used only under extremely strict contraceptive protection.
Symptomatic treatment should be given for other clinical features, and genetic counseling will help patients and families come to terms with the diagnosis and understand its mode of occurrence.