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 conditionthat only affects females

• This condition is caused by an abnormalchromosome and affects about one inevery 2,500 baby girls, but is much morecommon among pregnancies that do notsurvive to term [miscarriages andstillbirths]

• Turner’s syndrome was named after DrHenry turner the endocrinologist in year1938

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 orsperm so when an abnormal egg unites with a normal sperm to form anembryo that embryo ends up missing one of the sex chromosome (X ratherthan 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 inUnited states

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

• 1/2500 female births are related to turnersyndrome

DIAGNOSIS OF TURNER SYNDROME

• Turner syndrome may be suspected in pregnancy during an ultrasound test. Thiscan be confirmed by prenatal testing amniocentesis - to obtain cells from theunborn baby for chromosomal analysis. If a diagnosis is confirmed prenatally, thebaby 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 analysethe units that make up the child’s chromosomes.

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

TREATMENT FOR TURNER’S SYNDROME

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

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

• Babies born with a heart murmur or narrowing of the aorta may need surgeryto correct the problem. A heart expert (cardiologist) will assess and follow upany 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 thepediatrician. 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 thesyndrome in 1866.

• Down syndrome is one of the first symptomcomplexes associated with mental retardationto be identified as a syndrome.

• Down syndrome is a congenital conditioncaused by an extra chromosome. The presenceof an extra number 21 chromosome causes thedistinctive facial features, physicalcharacteristics and the cognitive impairmentsseen in people with Down syndrome

• People with Down syndrome may have a variety of birth defects. About halfof 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 severalmedical conditions. These include gastroesophageal reflux, which is abackflow of acidic stomach contents into the esophagus

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

CAUSES OF DOWN’S SYNDROME

• The most common form of Down syndrome is known as Trisomy 21, acondition where individuals have 47 chromosomes in each cell instead of 46.This is caused by an error in cell division called nondisjunction, which leaves asperm or egg cell with an extra copy of chromosome 21 before or atconception. 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 andtranslocation. Mosaic Down syndrome results when some cells in the bodyare normal while others have Trisomy 21. Robertsonian translocation occurswhen part of chromosome 21 breaks off during cell division and attaches toanother 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 orshortly after birth. The diagnosis is always based on the presence of an extranumber 21 chromosome on a karyotype

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

• If the doctor suspects that the baby has Down syndrome, a chromosome testcalled a karyotype, will be ordered. It usually takes a few days to get theresults of this blood test. It is almost always a shock when a baby isdiagnosed 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 commongenetic condition found in males only. Many boys with Klinefelter syndromehave no signs or symptoms, and some don't even know they have it untillater in life

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

• Klinefelter syndrome is named after Dr. Henry Klinefelter, who firstdescribed a group of symptoms found in some men with the extra Xchromosome. 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 Xchromosome.

• Of the 23 pairs of chromosomes, one pair is calledthe sex chromosomes because they determine aperson’s sex. One sex chromosome is inheritedfrom the mother and the other from the father.Mothers always pass on an X chromosome, butfathers can pass on an X or a Y chromosome.

• The normal male chromosome arrangement is46XY, but men with Klinefelter’s syndrome have47XXY. The extra X chromosome can come fromeither parent.

In young boys with the condition, the followingproblems 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 toENDOCRINOLOGIST

• Main treatment for Klinefelter's syndrome is with testosterone to boost thelow 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, youwill 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.