Your genes, also known as deoxyribonucleic acid (DNA), contribute to defining you as a person. They determine your appearance, your personality and your health condition. Sometimes, environmental or hereditary factors can play a role in interfering with this individual blueprint and genetic diseases result. Noonan syndrome, Down syndrome and Cri du chat syndrome are examples of genetic diseases.
Noonan Syndrome
According to the Mayo Clinic, Noonan syndrome is a type of condition that affects your child's development. Your child can inherit an altered gene or your child's genes may spontaneously alter. The altered genes involved in Noonan's syndrome include the PTPN11 gene, the SOS1 gene, the RAF1 gene and the KRAS gene.
Manifestations of Noonan's syndrome include low-set ears, wide eyes that slant downward and a short neck. Those characteristics occur in the early stages of infancy. As your child gets older, signs of Noonan's syndrome include a bulbous nose, lack of facial expression, a pointed chin and a prominent neck. According to the Mayo Clinic, Noonan syndrome sufferers have an increased chance of developing heart problems, learning disabilities, visual problems, bleeding and delayed puberty.
Down Syndrome
Down syndrome, another genetic disease, occurs in 1 in 700 or 800 infants, according to the Mayo Clinic. Signs of Down syndrome include a protruding tongue, a flat face, a small head (microcephaly), eyes that slant upward, strangely shaped ears and short fingers. Down syndrome sufferers can also develop short fingers and poor muscle tone.
Typically, your cells each have 23 chromosomes (a type of genetic material). In Down syndrome, you have an extra version of chromosome 21.
According to the Mayo Clinic, Down syndrome puts you at risk for heart defects, leukemia (a type of blood cancer), infectious diseases like pneumonia, obesity, hearing loss and visual problems. Down syndrome sufferers can now live to be more than 50 years old.
Cri Du Chat Syndrome
According to MedlinePlus, Cri du chat syndrome is a rare genetic disease caused by the lack of chromosome 5 (a specific gene in your cells). Specifically, you are missing the telomerase reverse transcriptase enzyme that is involved in regulating cell growth.
Manifestions of Cri du chat syndrome in your infant include a high-pitched cry that sounds like a cat, mental retardation, a small jaw (micrognathia), eyes that are wide apart, a low birth weight and a downward slanting of the eyes, according to MedlinePlus. This syndrome can also cause your child to develop webbing of his fingers or toes and abnormally shaped ears.
