Cockayne syndrome in Child
Alerts and Notices
SynopsisCockayne syndrome (CS) is a rare autosomal recessive multisystem disorder that presents with a constellation of findings including photosensitivity, growth retardation, and progressive neurologic deterioration. Patients with CS can be classified into 3 types depending on their age of onset and severity of disease. CS type I affects 80% of CS patients with onset of symptoms at birth to 2 years of age and life expectancy in the second to third decades. CS type II has symptoms at birth with a life span of only 5-6 years. CS type III has a late onset with first symptoms presenting at 3-4 years of age and mild subtype with mean age of death at 30 years.
An early finding in patients with CS is growth retardation followed by deafness, loss of subcutaneous fat, and eventually cachexia, giving this syndrome its characteristic physical stigmata of a "cachectic dwarf."
Common additional findings include cataracts, progressive pigmentary retinopathy, dental caries, photosensitivity, and neurodevelopmental changes including white matter involvement. Early presentation with cataracts (ie, prior to age 3) in patients with CS seems to be associated with a more severe phenotype. Cause of death in patients with CS is variable. The leading cause of death is respiratory infection.
CS, like xeroderma pigmentosum (XP) and trichothiodystrophy, is a nucleotide excision repair disorder. In contrast to XP, skin cancers on sun-exposed areas are not observed in patients with CS. However, a dozen affected patients with clinical features of both CS and XP have been described and these patients are at high risk for the development of cutaneous neoplasms due to failure of DNA excision repair gene.
Q87.19 – Other congenital malformation syndromes predominantly associated with short stature
21086008 – Cockayne syndrome
Differential Diagnosis & PitfallsAlong with Bloom syndrome, Rothmund-Thomson syndrome, XP, and trichothiodystrophy, CS is one of the inherited photosensitivity disorders associated with defective DNA nucleotide excision repair or chromosome instability.
- Bloom syndrome – Characterized by telangiectasias and facial erythema mimicking lupus erythematosus, photosensitive eruptions, and a specific mutation in the gene BLM encoding RecQ helicase. Patients lack the cachectic appearance of patients with CS and present within the first few months of life.
- Rothmund-Thomson syndrome – Characterized by alopecia, poikiloderma, dental dysplasia, and short stature. Patients lack the characteristic facies associated with CS.
- Trichothiodystrophy – Characterized by photosensitivity, ichthyosis, brittle hair, intellectual impairment, decreased fertility, and short stature. Patients lack the cachectic appearance of patients with CS.
- Hartnup syndrome – Characterized by photodistributed erythema and scale on the forehead, cheeks, and dorsal hands. Disease is caused by decreased tryptophan absorption. Normal stature and body habitus help to distinguish from CS.
- Progeria – Presents early in the first to second year of life with scleroderma-like skin changes. Patients characteristically display a large cranium with a thin, beaked nose.
Cockayne syndrome in Child