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| The greater the obstacle, the more glory in overcoming it. - Moliere |
Chromosomal anomalies are believed to be the single most common cause of miscarriages. It is estimated that more than half of all miscarriages are as a result of chromosomal abnormalities.
Did you know that trisomy can occur in any of the 23 pairs of chromosomes? While trisomy may occur in any chromosome, the survival rates are low -- but not impossible.
Trisomy 21 (Down Syndrome)
Down syndrome is the most common trisomy seen in newborns. Typically, there is a higher survival rate with Trisomy 21 but it too carries a significant risk of miscarriage.
Children with Down Syndrome have very distinct facial features, short hands with a single crease in the palm, poor muscle tone, excessive flexibility, small white spots on the iris of the eye called Brushfield's spots, short stature, mild to moderate cognitive impairment.
Complications associated with Down Syndrome include heart defects, gastrointestinal defects, immune disorders, sleep apnea, obesity, and dementia.
Life spans have increased dramatically over the years. Some people with Down syndrome can now live more than 60 years.
Children with Down Syndrome have very distinct facial features, short hands with a single crease in the palm, poor muscle tone, excessive flexibility, small white spots on the iris of the eye called Brushfield's spots, short stature, mild to moderate cognitive impairment.
Complications associated with Down Syndrome include heart defects, gastrointestinal defects, immune disorders, sleep apnea, obesity, and dementia.
Life spans have increased dramatically over the years. Some people with Down syndrome can now live more than 60 years.
Trisomy 18 (Edwards syndrome)
Trisomy 18 occurs in approximately 1 in 6,000 live births. making it about ten times rarer than Down syndrome. Most cases of trisomy 18 are caused by an extra number 18 chromosome.
Children with trisomy 18 have physical birth defects. Most infants with trisomy 18 will have some sort of heart defect, and some may have kidney, lung and diaphragm abnormalities.
Trisomy 13 (Patau syndrome)
Trisomy 13 (Patau syndrome) is the third most common autosomal abnormality among newborns, following Down syndrome (trisomy 21) and Edwards syndrome (trisomy 18). Most cases result from total trisomy 13 with a very small proportion of trisomy 13 being caused by mosaicism and translocation.
Children with trisomy 13 can have cleft lip and palates, extra fingers and toes, malformed and rotated internal organs, severe congenital heart defects, and severe brain abnormalities.
47, XXY Syndrome (Klinefelter syndrome)
Klinefelter syndrome, 47, XXY, or XXY syndrome, is a condition caused by an extra X chromosome.
Affected individuals have two X chromosomes and one Y chromosome. Many individuals are unaware that they have Klinefelter syndrome as the differences due to having an extra X chromosome are not very obvious and often go undetected.
The main problems seen in Klinefelter syndrome are small testicles and reduced fertility. A variety of other physical and behavioral differences are common; however, the severity of these symptoms can vary from person to person.
47, XYY Males
Some boys are born with an extra Y chromosome and have a 47, XYY karyotype. Most often, this extra Y chromosome causes no unusual physical features or medical problems. Males with 47, XYY syndrome can sometimes be taller than average and may have an increased risk of learning disabilities as well as delayed speech and language skills. Developmental delays and behavioral problems are also possible, but these characteristics vary widely among affected boys and men. Most males with 47, XYY syndrome have normal sexual development and are able to conceive children.
47, XXX ( Triple-X, Trisomy X, and XXX Syndrome)
Some girls are born with triple X syndrome. Triple X syndrome often has no associated physical features or medical problems. A small proportion of women with the condition may have menstrual irregularities as well as learning disabilities, delayed speech, and compromised language skills. However, many individuals with 47, XXX syndrome have completely normal physical and mental development.
Trisomy 15.
Trisomy 15 is rare. Most pregnancies with trisomy 15 end in early miscarriage. In pregnancies that have progressed, the fetus often has abnormalities of their facial and cranial features, hands and feet, and growth delays. Trisomy 15 has been linked to Prader-Willi syndrome.
Trisomy 16
Trisomy 16 is the most common autosomal trisomy seen in miscarriages and accounts for at least 15 percent of first trimester miscarriages. Most fetuses with trisomy 16 are lost around 12 weeks although a small percent may be lost in the second trimester. A few fetuses with mosaic trisomy 16 have survived until birth. Most of these infants have growth failure, psychomotor issues, and die early in infancy.
Trisomy 22
Complete trisomy 22 is the second most common chromosomal cause of miscarriages. Survival beyond the first trimester of pregnancy is rare. Complete trisomy 22 is very rare.
If you or your loved one has been diagnosed with a chromosome disorder and would like information regarding a specific karyotype, please visit UNIQUE at www.rarechromo.org.
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