Emanuel syndrome is a chromosomal disorder that occurs when children inherit extra cellular genetic material from chromosomes 11 and 22. Babies with this rare disorder are often born with cleft palates, abnormally small heads, kidney problems and facial disfigurement, among many other symptoms. Sometimes geneticists can prevent Emanuel syndrome by testing potential parents who might be at risk and by counseling them regarding their risk levels and expectations.
This disorder can occur if one of the child's parents has what is called a balanced translocation. A balanced translocation happens when chromosomes 11 and 22 evenly exchange genetic material during embryonic development. Each chromosome has the correct amount of material, so the parent does not suffer from any health problems. In Emanuel syndrome, the genetic switch becomes unbalanced when the translocation is passed down to the child.
Healthy babies are born with 46 chromosomes; babies with Emanuel syndrome have 47, including a "derivative 22" chromosome. This extra chromosome is created when part of chromosome 11 attaches to part of chromosome 22. A normal child has two copies of certain genes in each cell, but the extra chromosome causes the body to produce three copies of these genes.
The extra genes interfere with normal and healthy development. Many babies who are born with this syndrome do not grow as well as other children and might fail to gain weight. Babies usually have poor muscle tone and often have respiratory, kidney or heart problems. Baby boys might also have genital abnormalities.
These children have distinctive facial features that are characteristic of the disorder. Babies are born with deeply-set eyes, small chins and long upper lips. Some have ear deformities, abnormally small heads, cleft palates or extra skin on the back of the neck.
Mental retardation and developmental delays appear as the baby matures into childhood. Many children do not learn to walk until they are around five years of age. Hearing impairments are common, and most children do not learn to speak. The majority of these children have special healthcare needs.
Not every parent who has a balanced translocation will give birth to a child with this disorder. Female carriers who have already given birth to a child with Emanuel syndrome have an approximate six percent risk with each subsequent pregnancy, while males have a two to five percent risk. Doctors can perform prenatal testing to determine if the baby has Emanuel syndrome. A parent whose sibling has Emanuel syndrome might also consider genetic testing before beginning a family.