The prognosis for those with<unk>  is poor, as death typically occurs by the age of 12. The prognosis for<unk>  varies by disease type. There are three types of<unk>  according to the severity and onset of the symptoms. However, the differences between the types are not always clear-cut, and some researchers believe the signs and symptoms reflect a spectrum instead of distinct types:<unk>  Type A <unk> A) is marked by normal development until a child is 1 or 2 years old, at which point growth slows and developmental delays are noticed. Symptoms are not apparent until they are 1 year. Life expectancy for type A is approximately 10 to 20 years. These symptoms are seen in<unk>  type 1 children.<unk>  type B <unk> B), also known as "cerebro-oculo-facio-skeletal (COFS) syndrome" (or "Pena-Shokeir syndrome type B"), is the most severe subtype. Symptoms are present at birth and normal brain development stops after birth. The average lifespan for children with type B is up to 7 years of age. These symptoms are seen in<unk>  type 2 children.<unk>  type C <unk> C) appears later in childhood with milder symptoms than the other types and a slower progression of the disorder. People with this type of<unk>  live into adulthood, with an average lifespan of 40 to 50 years. These symptoms are seen in<unk>  type 3.
Cockayne syndrome
Xeroderma pigmentosum
ATR-X syndrome
ATR-16 syndrome
Cornelia de Lange syndrome
MEDNIK syndrome
Treacher Collins syndrome
LIG4 syndrome