GENETIC DISORDERS

TURNER’S SYNDROME

DOWN’S SYNDROME

KLINEFELTER’S SYNDROME

SAURABH and SWATI

WHAT IS TURNER’S SYNDROME

• Turner’s syndrome is a genetic condition that only affects females

• This condition is caused by an abnormal chromosome and affects about one in every 2,500 baby girls, but is much more common among pregnancies that do not survive to term [miscarriages and stillbirths]

• Turner’s syndrome was named after Dr Henry turner the endocrinologist in year 1938

CAUSES OF TURNER SYNDROME

• Turner’s syndrome is typically caused by nondisjunction

• A pair of sex chromosome fails to separate during the formation of egg or sperm so when an abnormal egg unites with a normal sperm to form an embryo that embryo ends up missing one of the sex chromosome (X rather than XX)

• "45X” meaning that an individual has 44 autosomes and a single X chromosome

KARYOTYPE FOR TURNER’S SYNDROME

HOW COMMON IS TURNER SYNDROME

• Turner syndrome affects 71000 females in United states

• Most pregnancies that are affected by turner’s syndrome results in miscarriages 10% of miscarriages are caused by turner syndrome

• 1/2500 female births are related to turner syndrome

DIAGNOSIS OF TURNER SYNDROME

• Turner syndrome may be suspected in pregnancy during an ultrasound test. This can be confirmed by prenatal testing amniocentesis - to obtain cells from the unborn baby for chromosomal analysis. If a diagnosis is confirmed prenatally, the baby may be under the care of a specialist pediatrician immediately after birth.

• Diagnosis is confirmed by a blood test called a karyotype. This is used to analyse the units that make up the child’s chromosomes.

• For a child with Turner syndrome, the earlier the diagnosis, the better the prospects for treatment. Children who are shorter than normal are often seen by a pediatric endocrinologist, who is a doctor specializing in treating children with growth problems.

TREATMENT FOR TURNER’S SYNDROME

• Growth hormone injections are beneficial in some individuals with Turner syndrome. Injections often begin in early childhood and may increase final adult height by a few inches.

• Estrogen replacement therapy is usually started at the time of normal puberty, around 12 years to start breast development

• Babies born with a heart murmur or narrowing of the aorta may need surgery to correct the problem. A heart expert (cardiologist) will assess and follow up any treatment necessary.

• Girls who have Turner syndrome are more likely to get middle ear infections. Repeated infections may lead to hearing loss and should be evaluated by the pediatrician. An ear, nose and throat specialist (ENT)

REFRENCES FOR TURNER’S SYNDROME

• Introduction of Turner’s syndrome

http://www.nhs.uk/conditions/turners syndrome/page/introduction.aspx • diagnosis and treatment of Turners syndrome

http://www.medicinenet.com/turner-syndrome/article.html • How common is turners syndrome

http://turnerssyndrome.org/learn-about-ts/fact-sheet • Turner’s syndrome clinical features

http://www.norditropinhcp.com/turnersyndrome.aspx • Monosomy X-turner’s syndrome45,X

http://www.meddean.luc.edu/lumen/med/genetics/disease/turner.html

Karyotype for turner's syndrome

http://www.net-infirmers.com/le-syndrome-de-turner-enquelques-mots

Causes for turner’s syndrome

http://learn.genetics.Utah.edu/content/disorders/chromosomal/turner/html

WHAT IS DOWN’S SYNDROME

• Dr. John Langdon Down described the syndrome in 1866.

• Down syndrome is one of the first symptom complexes associated with mental retardation to be identified as a syndrome.

• Down syndrome is a congenital condition caused by an extra chromosome. The presence of an extra number 21 chromosome causes the distinctive facial features, physical characteristics and the cognitive impairments seen in people with Down syndrome

• People with Down syndrome may have a variety of birth defects. About half of all affected children are born with a heart defect. Digestive abnormalities, such as a blockage of the intestine

• Individuals with Down syndrome have an increased risk of developing several medical conditions. These include gastroesophageal reflux, which is a backflow of acidic stomach contents into the esophagus

• Delayed development and behavioral problems are often reported in a children with down's syndrome

CAUSES OF DOWN’S SYNDROME

• The most common form of Down syndrome is known as Trisomy 21, a condition where individuals have 47 chromosomes in each cell instead of 46. This is caused by an error in cell division called nondisjunction, which leaves a sperm or egg cell with an extra copy of chromosome 21 before or at conception. Trisomy 21 accounts for 95% of Down syndrome cases, with 88% originating from nondisjunction of the mother's egg cell.

• 5% of Down syndrome cases are due to conditions called mosaicism and translocation. Mosaic Down syndrome results when some cells in the body are normal while others have Trisomy 21. Robertsonian translocation occurs when part of chromosome 21 breaks off during cell division and attaches to another chromosome (usually chromosome 14).

HOW COMMON IS DOWN’S SYNDROME

• There are three types of Down syndrome: trisomy 21 (nondisjunction) accounts for 95% of cases, translocation accounts for about 4% and mosaicism accounts for about 1%.

• One in every 691 babies in the United States is born with Down syndrome • There are more than 400,000 people living with Down syndrome in the United

States. Down syndrome occurs in people of all races and economic levels. The incidence of births of children with Down syndrome increases with the age of the mother. But due to higher fertility rates in younger women, 80% of children with Down syndrome are born to women under 35 years of age.

DIAGNOSIS FOR DOWN’S SYNDROME

• Down syndrome is diagnosed one of two ways, either during pregnancy or shortly after birth. The diagnosis is always based on the presence of an extra number 21 chromosome on a karyotype

• The diagnosis of Down's syndrome is usually made soon after birth because of some subtle differences in the baby's appearance.

• If the doctor suspects that the baby has Down syndrome, a chromosome test called a karyotype, will be ordered. It usually takes a few days to get the results of this blood test. It is almost always a shock when a baby is diagnosed with Down syndrome

TREATMENT FOR DOWN’S SYNDROME

• Providing support and treatment for a patient with Down syndrome is meant to improve their quality of life.

• Medical conditions associated with Down syndrome, including those affecting the heart or the gastrointestinal system, may require evaluation and care, sometimes requiring surgery.

• As the patient ages, the care and support needed will depend upon the intellectual ability and physical function achievable by the individual.

REFERENCES FOR DOWN’S SYNDROME

Introduction of down’s syndrome

http://downsyndrome.about.com/od/downsyndrome

http://ghr.nlm.nihgov/condition/down-syndrome

Causes of down’s syndrome

http://www.medicalnewstoday.com/articles/145554.php

Figure of trisomy 21

http://www.larasig.com/node/3645

Symptoms for down’s syndrome

http://www.rayur.com/chromosomal-disorder-down_syndrome-trisomy-21.html

REFERENCES

How common is down’s syndrome

http://www.ndss.org/down-syndrome/down-syndrome-facts/html

Diagnosis for down’s syndrome

http://downsyndrome.about.com/od/diagnosing/down’ssyndrome/a/diagnossiess

Treatment for down’s syndrome

http://www.medicinenet.com/down-syndrome_overview/page3.html

WHAT IS KLINEFELTER’S SYNDROME

• Klinefelter syndrome, also known as XXY syndrome, is a fairly common genetic condition found in males only. Many boys with Klinefelter syndrome have no signs or symptoms, and some don't even know they have it until later in life

• Klinefelter syndrome typically causes a boy's testicles to grow at a slower rate than those of other boys. It prevents testicles from producing normal amounts of sperm and the hormone testosterone.

• Klinefelter syndrome is named after Dr. Henry Klinefelter, who first described a group of symptoms found in some men with the extra X chromosome. Even though all men with Klinefelter syndrome have the extra X chromosome, not every XXY male has all of those symptoms.

CAUSES OF KLINEFELTER’S SYNDROME

• Men with Klinefelter’s syndrome have an extra X chromosome.

• Of the 23 pairs of chromosomes, one pair is called the sex chromosomes because they determine a person’s sex. One sex chromosome is inherited from the mother and the other from the father. Mothers always pass on an X chromosome, but fathers can pass on an X or a Y chromosome.

• The normal male chromosome arrangement is 46XY, but men with Klinefelter’s syndrome have 47XXY. The extra X chromosome can come from either parent.

In young boys with the condition, the following problems may occur:• difficulties with speech and reading • delayed motor development • reduced attention span • poor muscle tone • behavioral problems.

HOW COMMON IS KLINEFELTER’S SYNDROME

• Between 1 in 500 and 1 in 1,000 boys are born with Klinefelter’s syndrome

DIAGNOSIS OF KLINEFELTER’S SYNDROME

• Diagnosis is confirmed using a blood test called a karyotype. This test checks the number and features of the chromosomes in a sample of cells from blood.

• A blood test is also carried out to determine levels of testosterone, luteinizing hormone (LH) and follicle stimulating hormone (FSH).

• Luteinizing hormone stimulates the production of testosterone. In many men with Klinefelter’s syndrome, levels of lutenizing hormone are raised, but testosterone levels are borderline or below normal. Follicle stimulating hormone levels are also raised, which can be a sign of damage to the sperm-producing tubes in the testes.

TREATMENT OF KLINEFELTER’S SYNDROME

• Any individual suffering from klinefelter's syndrome should be referred to ENDOCRINOLOGIST

• Main treatment for Klinefelter's syndrome is with testosterone to boost the low levels. Testosterone can help to:

Increase your strength and build a more muscular body type.

Increase facial and pubic hair growth.

Increase your libido (sex drive).

Enlarge your testes. • If you have Klinefelter syndrome and you are considering having children, you

will need to see an infertility specialist.

REFERENCES FOR KLINEFELTER’S SYNDROME

• Introduction of klinefelter’s syndrome

Http://kidshealth.org/parent/medical/endocrine/klinefelter-syndrome.html • Causes of klinefelter’s syndrome

Http://www.andrologyaustralia.org/reproductive-problems/klinefelters-syndrome/html • Karyotype of klinefelter’s syndrome

Http://rockyourchromosome.blogspot.in/2013/03/klinefelters-syndrome.charachteristics.html

REFERENCES KLINEFELTER’S SYNDROME

• Symptoms of klinefelter’s syndrome

Http://www.andrologyaustralia.org/reproductive-problems/klinefelters-syndrome/html • Diagnosis of klinefelter’s syndrome

Http://www.andrologyaustralia.org/reproductive-problems/klinefelters-syndrome/html • How common is klinefelter’s syndrome

Http://www.patient.co.uk./health/klinefelter-syndrome# • Treatment of klinefelter’s syndrome

Http://www.patient.co.uk./health/klinefelter-syndrome#

FINAL CONCLUSION

• Turner’s syndrome is genetic abnormality in which out of 46 chromosomes there are 44 autosomes and a single X chromosome (X rather than XX)

• Down’s syndrome is also know as trisomy 21 in which individual has 47 chromosomes instead of 46

• Klinefelter’s syndrome is also known as XXY syndrome normal male chromosome arrangement is 46XY, but men with Klinefelter’s syndrome have 47XXY.