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Edward’s syndrome

Alternative Names:Trisomy 18 (T18), Trisomy E or Edwards syndrome

Definition:
Edward’s syndrome is a genetic disorder caused by the presence of all or part of an extra 18th chromosome. It is named after John H. Edwards, who first described the syndrome in 1960. It is the second most common autosomal trisomy, after Down Syndrome, that carries to term.

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A rare genetic chromosomal syndrome where the child has an extra third copy of chromosome 18.
Trisomy 18 is caused by the presence of three – as opposed to two – copies of chromosome 18 in a fetus or infant‘s cells. The incidence of the syndrome is estimated as one in 3,000 live births. The incidence increases as the mother’s age increases.  Edwards syndrome is more severe than the more common Down syndrome. Edwards syndrome causes mental retardation and numerous physical defects that often cause an early infant death.The syndrome has a very low rate of survival, resulting from heart abnormalities, kidney malformations, and other internal organ disorders. Most fetuses are aborted before term, but a live birth with this condition occurs with a frequency around 1-in-3000.

Edwards’ syndrome occurs in around one in 6,000 live births and around 80 per cent of those affected are female. However, the majority of babies with the syndrome die before birth.

It affects people from all cultural backgrounds and becomes more likely with increasing maternal age.

Symptoms:
The features and problems that develop in children with Edwards’ syndrome vary from child to child.

Typically, a child will have a small head with characteristic facial features including a small jaw and mouth, upturned nose, widely spaced small eyes with narrow eyelid folds and drooping of the upper eyelids, and low-set, malformed ears.

The hands may be clenched, with the second and fifth fingers overlapping the other fingers, and the thumbs may be underdeveloped or absent. Webbing of the second and third toes may also occur.

In addition to these features, all systems of the body may be affected. Structural malformations of the heart, kidneys, brain, digestive tract and genitals may be present and cause the child difficulties. For example, children with the syndrome often have trouble feeding and breathing, and experience delay in growth and development. Infections of the lungs and urinary system are also common.

Diagnosis:
At birth, if physical characteristics suggest the possibility of Edwards’ syndrome, this can be confirmed with genetic testing.

An ultrasound during pregnancy can often identify foetal abnormalities, providing the opportunity for genetic testing by amniocentesis.

Treatment:
There’s no cure for Edwards’ syndrome, but medical treatment of symptoms is provided as required.

Treatment focuses on providing good nutrition, tackling infections – which arise frequently – and helping the heart to function better.

Many babies with Edwards’ syndrome have difficulties with feeding, so food may be given via a nasogastric tube or directly into the stomach through a gastrostomy. Where limb abnormalities affect movement, physiotherapy and occupational therapy can help.

Emotional support for parents and other members of the family is vital, as babies with Edwards’ syndrome have a shortened life expectancy. Few survive beyond their first year.

Prognosis:
In England and Wales, there were 495 diagnoses of Edwards’ syndrome (trisomy 18) in 2008/2009, of which 92% were made prenatally. There were 339 terminations, 49 stillbirths/miscarriages/fetal deaths, 72 unknown outcomes, and 35 live births. Because approximately 3% of cases of Edwards’ syndrome with unknown outcomes are likely to result in a live birth, the total number of live births is estimated to be 37 (2008/09 data are provisional). Only 50% of liveborn infants live to 2 months, and only 5–10% survive their first year of life. Major causes of death include apnea and heart abnormalities. It is impossible to predict the exact prognosis of a child with Edwards syndrome during pregnancy or the neonatal period. The median lifespan is 5–15 days. One percent of children born with this syndrome live to age 10, typically in less severe cases of the mosaic Edwards syndrome. The small percentage of babies with the full Edwards syndrome who survive birth and early infancy may live to adulthood, and children with mosaic or partial forms of this trisomy may have a completely different and much more hopeful prognosis.

Disclaimer: This information is not meant to be a substitute for professional medical advise or help. It is always best to consult with a Physician about serious health concerns. This information is in no way intended to diagnose or prescribe remedies.This is purely for educational purpose.

Resources:
http://www.ispub.com/journal/the_internet_journal_of_third_world_medicine/volume_4_number_1_53/article/edwards_syndrome_in_a_neonate_from_a_developing_country_reasons_for_concern_a_case_report.html
http://www.netdoctor.co.uk/ate/pregnancyandchildbirth/205249.html
http://www.wrongdiagnosis.com/e/edwards_syndrome/intro.htm
http://en.wikipedia.org/wiki/Edwards_syndrome
http://www.bbc.co.uk/health/physical_health/conditions/edwardssyndrome2.shtml

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Faulty Gene Causes Heart Attack Death

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A faulty gene variant that can cause heart attack mortalities also potentially opens the way for improved treatment following such attacks.
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“It’s been known for some time that a defective ACE2 gene is associated with high blood pressure, but our research has also clearly linked one variant of this gene to a greater likelihood of mortality after heart attack,” said lead researcher Barry Palmer of Otago University, Christchurch.

“This is particularly in middle aged males who have acute coronary syndromes, or reduced flow of blood to the heart,” he added.

Otago scientists carried out the study over three years on a large cohort of 1,075 people (males and females) recruited from hospitals. They found, after adjusting for variables such as age, that male patients are almost twice as likely to die if they had one particular (defective) variant of the ACE2 gene.

“This is the first time ever that this variant of the ACE2 gene has been identified in terms of survivability,” said Palmer. “It will be useful in terms of other research we’re doing on tailoring heart disease treatment more accurately to the patient.”

“If we can identify those people at greater risk we may be able to do more earlier on in their treatment, and it’s easy enough to identify if someone has this variant of the gene.”

Males are more prone than females to the effects of the ACE2 gene variant which is linked to reduced survival because of their chromosomal make-up. That’s because males have only one copy in each cell of the ACE2 gene on the X chromosome and none on the Y chromosome, whereas females have two X chromosomes, according to an Otago release.

This means that if a male has a defective ACE2 gene variant there is no complementary chromosome which can compensate for that ineffective gene. Females have an alternative copy of the gene on their second X chromosome which can compensate for the defective ACE2 gene, and provide normal blood pressure to the heart.

In its normal form on the X chromosome the ACE2 gene produces an enzyme which controls blood pressure by influencing hormone levels. It is only when that gene is defective that blood pressure may increase.

The research was published in the October issue of the American Heart Journal.

You may click to see:->FAMILIAL HYPERCHOLESTEROLAEMIA Cardiovascular disease

Sources: The Times Of India

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Of older moms and Down Syndrome

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India‘s urban elite has plenty of DINKs (Double Income, No Kids). These people get married later than their rural counterparts, often after they are financially and professionally independent and secure. They can afford the best, as far as pregnancy, antenatal care and delivery are concerned. Eventually, they limit their families to one or maybe two children for whom they wish to provide the best opportunities in life.

Under these circumstances, the birth of a child with Down’s Syndrome (trisomy 21 or mongolism) becomes an unbearable tragedy.

One in 800 children is born with Down’s Syndrome. Such children have a characteristic mongoloid  appearance at birth itself, irrespective of the parents’ ethnic backgrounds. The head may be smaller than normal with a sloping forehead, upward slanting eyes, a small flattened nose, low set ears, short stumpy fingers, a protuberant abdomen and a tongue which sticks out of a small mouth. Also, the palm shows just two lines instead of the usual three.

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Down’s Syndrome usually occurs spontaneously as a result of an anomaly during early embryonic cell proliferation producing an abnormal chromosome 21. During cell division it may have divided abnormally, producing three parts instead of the normal two. Sometimes a piece from the chromosome may have attached (translocated) itself to another chromosome.

These anomalies are more likely with increased maternal age at the time of the pregnancy. Many doctors and researchers consider the age 35 as the cut off.

The child shows all the typical features of Down’s Syndrome if all the cells contain the abnormal chromosomes. Sometimes the person may be a mosaic, with a mixture of normal and abnormal cells. The appearance may then be atypical.

The risk of recurrence is greater if the condition has arisen as a result of translocation. This is because one of the parents is then likely to be a carrier. The risk is around 3 per cent if the father is the carrier, and 12 per cent if the mother carries the abnormal gene. Also, a mother with a Down’s Syndrome child has a one per cent chance of producing another similarly affected child.

Life is difficult for children suffering from Down’s Syndrome as they often have subnormal intelligence. They may also have abnormalities in other organs like the heart. There may be blocks or malfunction of the gastrointestinal tract with constipation and intestinal bloating. Hearing loss or visual defects may also occur. The chromosomal abnormality causes a decreased immune response, causing frequent infections as the children grow. The incidence of leukaemia is 20 times greater than in the general population. Dementia too sets in during early adult life (around 40). All this means a lifetime of nurturing and extra care.

So does this mean that women should sacrifice education and professional careers for early marriage and childbirth?

Not really, as advances in medical science have made it possible to diagnose Down’s Syndrome during the antenatal period itself.

Ultrasound examination during the first trimester has a detection rate of approximately 95 per cent of all Down’s Syndrome cases. The measurement of nuchal translucency — the size of a collection of fluid at the base of the foetal neck  correlates with the risk of Downs Syndrome. Other markers like the size of the head, the nose, the presence or absence of heart and intestinal defects can be evaluated with a scan. The presence of several abnormal markers may be an indication of Down’s Syndrome.

Moreover, certain blood tests performed on the mother can show abnormal results if the foetus is affected. Of these, the one commonly available in India is the alpha-fetoprotein level which tends to be less than normal in Down’s Syndrome.

To confirm the diagnosis, the chromosomes of the foetus can be examined. This can be done with amniocentesis (an examination of the cells in the amniotic fluid that surrounds the baby in the uterus). The diagnosis takes two weeks.

The cells of the placenta can be also tested during the 10th and 12th weeks of pregnancy by Chorionic Villus Sampling (CVS). If a rapid diagnosis is required, Percutaneous Umbilical Blood Sampling (PUBS) can be done after 18 weeks of gestation. Each of these three tests is 98 to 99 per cent accurate in diagnosing Down’s Syndrome. However, all these tests carry a risk of miscarriage.

After birth, Down’s Syndrome is suspected because of the typical appearance of the baby. It is confirmed by karyotyping or checking the baby’s chromosomes to demonstrate the extra chromosome in the cells.

Unfortunately, much of this high-tech diagnosis is out of reach for the average Indian woman. Financial constraints, poor education and lack of facilities are major drawbacks to good antenatal care and prenatal diagnosis.

Source:Thr Telegraph (Kolkata,India)

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Insights: In a Man’s Offspring, a Clue to Prostate Cancer

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Men who have only daughters may be at greater risk for prostate cancer than those who have at least one son, a new study reports, and the reason may be an alteration in the Y chromosome, the male sex chromosome.

Prostate Cancer in Fathers With Fewer Male Offspring: the Jerusalem Perinatal Study Cohort (Journal of the National Cancer Insitute)Researchers recorded the sex of the offspring of 38,934 Israeli men who had children from 1964 to 1976, and then followed the fathers through 2005, during which time 712 developed prostate cancer. After adjusting for other variables, they found that those with no sons were almost one and a half times as likely to have developed the disease as those with at least one son. The more daughters they had without having any sons, the more their risk increased.

Because the inability to produce male children is associated with alterations in the Y chromosome, this suggests that the chromosome may be involved in prostate cancer risk.
Still, said Dr. Susan Harlap, the lead author and a professor of clinical epidemiology at Columbia,  The main reason a man has male or female children, even in runs of one sex, is chance. She said she did not recommend extra prostate screening for men with only daughters.

The researchers acknowledge that their study, published Jan. 3 in The Journal of the National Cancer Institute, gathered no information about family history of prostate cancer. In addition, they studied a specific group of men, and it may not be possible to generalize the results to other populations.

Prostate cancer is a huge mystery,  Dr. Harlap said, not like lung or colon cancer, where we have a pretty good idea about causes. Our study gives a hint to look at the Y chromosome, and maybe the X chromosome, too, while you  are at it.

Source:The New York Times

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