In infancy and early childhood, growth retardation and obesity are prevelant as well. The Central Nervous System is affected as well. At birth, hypotonia is developed and also, people with Down Syndrome are more likely to develop Alzheimer Disease. Developmental and mental retardation take form and they experience a decrease in cognitive function, as well as tending to have a decreased sensitivity to pain. Lastly, the immune system is affected and sometimes compromised Infants with Down Syndrome are 20% more likely to develop Leukemia. Also, they have a more compromised immune system and are prone to Thyroid Dysfunction. Males with Down Syndrome are also sterile and people diagnosed with Down Syndrome have reduced longevity.
Epstein was most famous for his “Gene Dosage Effect Hypothesis”. The Hypothesis basically stated that having extra genes created extra proteins which then result in the manifestation of Down Syndrome. At first, his hypothesis was rejected by many, but it was eventually proven correct and is now the basis a tremendous advancement in the understanding of Down Syndrome and searching for a treatment (Epstein & Feaster,