Patients with CHILD syndrome (Congenital Hemidysplasia with Ichthyosiform erythroderma and Limb Defects [OMIM #308050], have a specific lateralization pattern and midline demarcation of an inflammatory epidermal nevus. These skin lesions are usually present at birth and persist throughout life. Alopecia and nail abnormalities are also common. Limb defects (typically hypoplasia or aplasia) occur ipsilateral to the skin defects. Epiphyseal stippling may be noted on radiographs in infancy.
Mutations of the NSDHL [OMIM #300275] gene that codes for a NADH steroid dehydrogenase-like protein have been identified in patients with CHILD syndrome. Bornholdt, et al  found mutations in the NSDHL gene in 14/14 patients with a clinical and histopathological diagnosis of CHILD syndrome. Patients with CHILD syndrome have increased levels of 4-methyl- and carboxysterols in cultured lymphoblasts. Sterol analysis of plasma and scales from skin lesions is currently used for diagnosis and is available at the Clinical Mass Spectrometry Laboratory at Kennedy Krieger Institute. This test may also distinguish CHILD syndrome from CDPX2 (X-linked dominant chondrodysplasia punctata), a phenotypically similar condition caused by mutations in the EBP (emopamil binding protein) gene.
Deletions and/or duplications of the NSDHL gene as causative of CHILD syndrome have been reported.