Question: What is (are) Cockayne syndrome ?
Answer: Cockayne syndrome is a rare condition which causes short stature, premature aging (progeria), severe photosensitivity, and moderate to severe learning delay. This syndrome also includes failure to thrive in the newborn, microcephaly, and impaired nervous system development. Other symptoms may include hearing loss, tooth decay, and eye and bone abnormalities. Cockayne syndrome type 1 (type A) is sometimes called classic or "moderate" Cockayne syndrome and is diagnosed during early childhood. Cockayne syndrome type 2 (type B) is sometimes referred to as the severe or "early-onset" type. This more severe form presents with growth and developmental abnormalities at birth. The third type, Cockayne syndrome type 3 (type C) is a milder form of the disorder. Cockayne syndrome is caused by mutations in either the ERCC8 (CSA) or ERCC6 (CSB) genes and is inherited in an autosomal recessive pattern. The typical lifespan for individuals with Cockayne syndrome type 1 is ten to twenty years. Individuals with type 2 usually do not survive past childhood. Those with type 3 live into middle adulthood.
Source: GARD

Question: What are the symptoms of Cockayne syndrome ?
Answer: What are the signs and symptoms of Cockayne syndrome? The Human Phenotype Ontology provides the following list of signs and symptoms for Cockayne syndrome. If the information is available, the table below includes how often the symptom is seen in people with this condition. You can use the MedlinePlus Medical Dictionary to look up the definitions for these medical terms. Signs and Symptoms Approximate number of patients (when available) Abnormal blistering of the skin 90% Abnormality of the nose 90% Carious teeth 90% Cognitive impairment 90% Cutaneous photosensitivity 90% Deeply set eye 90% Hyperreflexia 90% Hypertonia 90% Incoordination 90% Macrotia 90% Microcephaly 90% Peripheral neuropathy 90% Prematurely aged appearance 90% Retinopathy 90% Sensorineural hearing impairment 90% Short stature 90% Abnormal hair quantity 50% Abnormality of the foot 50% Aplasia/Hypoplasia of the skin 50% Atypical scarring of skin 50% Cerebral calcification 50% Cerebral cortical atrophy 50% Chorioretinal abnormality 50% Decreased nerve conduction velocity 50% Dental malocclusion 50% Disproportionate tall stature 50% EEG abnormality 50% Fine hair 50% Generalized hyperpigmentation 50% Hypertension 50% Kyphosis 50% Large hands 50% Limitation of joint mobility 50% Strabismus 50% Tremor 50% Abnormality of pelvic girdle bone morphology 7.5% Abnormality of retinal pigmentation 7.5% Abnormality of the palate 7.5% Aplasia/Hypoplasia affecting the eye 7.5% Breast aplasia 7.5% Cataract 7.5% Cryptorchidism 7.5% Delayed eruption of teeth 7.5% Glomerulopathy 7.5% Hypertrophic cardiomyopathy 7.5% Nephrotic syndrome 7.5% Optic atrophy 7.5% Oral cleft 7.5% Platyspondyly 7.5% Seizures 7.5% Telangiectasia of the skin 7.5% The Human Phenotype Ontology (HPO) has collected information on how often a sign or symptom occurs in a condition. Much of this information comes from Orphanet, a European rare disease database. The frequency of a sign or symptom is usually listed as a rough estimate of the percentage of patients who have that feature. The frequency may also be listed as a fraction. The first number of the fraction is how many people had the symptom, and the second number is the total number of people who were examined in one study. For example, a frequency of 25/25 means that in a study of 25 people all patients were found to have that symptom. Because these frequencies are based on a specific study, the fractions may be different if another group of patients are examined. Sometimes, no information on frequency is available. In these cases, the sign or symptom may be rare or common.
Source: GARD