DOWN SYNDROME

 

DOWN SYNDROME

Introduction:

            Down syndrome is a genetic disorder.  This condition its name from Dr.Langdon  Down. who first described it in the clinical lecture reports of the London hospital in 1866.  The chromosomal basis was established in1959 by Lejeune and his colleagues.

            This is the commonest chromosomal disorder occurring with frequency of 1:800 to 1:1000 new borns.

            Down syndrome affects a baby’s normal physical development and cause mild to moderate learning difficulties.

Definition:

            Is a common birth defect that is usually deu to an extra chromosome 21 [Trisomy] [Trisomy:- Agenetic disorder in which a person has three copies of a chromosome instead of two].

Causes:

            Extra copy of chromosome 21.  This condition arises in one of 3 ways.

1. Non-Diconjuction [94%]

            Ovum to be fertilized contains 24 chromosomes i.e., an extra 21^st chromosome, which resulted from unequal chromosome distribution at cell division (Meiosis) in ovary.  This type of abnormality occurs particularly in older women.  Towards end of reproductive life.  Abnormal spermatozoa produced by males are non-competitive with normal sperm, but only one ovum released each month and if abnormal if may be fertilized.  Hence only maternal age important in pathogene.

2.  Mosacism(3%)

            Unequal distribution of chromosomes during cell division after fertilization.  Some cells then have 46 [ Normal] chromosomes, other 47 [trisomy].

3.Transloctaion [3%]

            The transfer of a segment of chromosome to a different site on the same chromosome or to a different chromosome which causes congenital abnormality.

Clinical Manifestation

1.       Pure trisomy 21 [ 47 XX or XY  + 21]

2.      The children are mental and physical retardation.

3.      Thyroid dysfunction is difficult to detect clinically and 30% of children have sub-clinical hypothyroidism.

4.      Congenital heart disease present in 40% case.

5.      Visual and hearing defects include cataract.

6.      Squint

7.      Nystagmus

8.      About 40-60% have conductive hearing loss and 20-30% have sensorineural hearing loss.

9.      Intestinal atresia.

10. Hirsch sprungs disease

11. Recurrent respiratory tract infections and increased risk of leukemia.

12. General – Hypotonia, Small Stature, Mental retardation but usually sociable and happy

13. Head – Flat Occiput

Face – Flat nasal bridge, small nose

Ears – Small, sometimes protruding

Neck – Short Abundant neck skin

Eyes – Upward slant of palpebral fissures, especially blue eyed        subjects (Brush fields spots)

Mouth – Open protruding tongue, Hypoplasia of teeth

Hands – Short broad small fingers

Feet – Wide space

Skin – Dry skin in older individuals hair soft and sparse

Heart – A cyanotic variable defect

Genitalia – Small genitalia, crytorchidism and Infertility in males

Gastrointestinal – Duodenal Atresia, oesophageal atresia

Blood – Lymphoblastic leukemia is 1%

 

Diagnosis

1.       Chorionic villus sampling (CVS) 10 to 13 weeks of pregnancy.

2.      Screening tests during pregnancy blood test

·        Alpha fetoprotein

·        Human chorionic gonadotropin [ HCG]

·        Inhibin A

·        Ultrasound

3.      Amniocentesis

Medical Management

1.       Typically start in early childhood and aim to help people live productives and fulfilling lives.

2.      Speech therapy to improve the ability to communicate.

3.      Physical therapy to help strengthen muscles and improve motor skills

4.      Occupational therapists

5.      Group therapy may e beneficial

6.      In early infancy, child needs some care as any other baby.  Retardation in achieving milestones becomes evident later.

7.      Parents need support particularly during first year of life.  If they are to accept child emotionally.

8.      Early training with specific limited objectivities helps to both mother and child. Eg:-feeding, dressing, toilet training, etc

9.      Older child needs special schools, occasional social admissions to suitable hospital or home to allow parents holiday alone.

10. Medical problems (Ex) frequent respiratory infections, cardiac defect treated on individual merits.

Complications:

1.    Dementia

2.    Heart defects

3.    Hearing loss are all potential

4.    Blood disorders that can include leukemia. (Cancer of the Blood)

5.    Immune System Problem

Summary:

          Down syndrome is a condition in which a person is born with an extra copy of chromosome 21 people with down syndrome can have physical problems as well as intellectual disabilities.

 

Bibliography

Sl. No.	Name of the Book	Name of the Author	Page Nos.	Edition
1	Child Health Nursing	Manoj Yadav	503-504
2	Essential Pediatric Nursing	Piyush Gupta	507	2nd Edition

 

Internet:

·        www.hse.ie

·        www.medicine.com

·        www.mayoclinic.org

·        www.my.clevelandclinic.org

·        www.uptodate.com

 

TURNER’S SYNDROME

Introduction:

            The turner’s syndrome is also called gonadal dysgenesis.  It is a condition that effects only females. Results when one of the X chromosomes (sex chromosomes) is missing or partially missing.

            The turner syndrome can cause a variety of medical and developmental problems.  Including short height, failure of ovaries to develop and heart defects.

Definition:

            It is a chromosomal condition that effects development in females.

Incidence:

            1 in 2500 live births.

Etiology

            Maldistribution of chromosomes cell division leading to individual with 45 chromosomes a single “X” being only sex chromosome present.

Clinical Manifestation

1.       Short statured females with varying clinical features.

2.      Neck – Short and webbed neck and congenital lyphedema

3.      Chest – Broad with widely spaced nipples

4.      Skin – May show excessive pigmented nevi

5.      Nails – Narrow and hyperconvex

6.      Face – High Arched palate and prominent ears.

7.      Trunk and limbs – Broad chest, webbing neck widely spaced nipples

8.      Gonads – Ovarian dysgenesis or complete absence of germinal tissue.

9.      Others – Cardiac defect (20%) are present in a number of children coarctation of aorta or valvular stenosis or prolapsed pose a problem when the child grows up.

10. General – Low birth weight, growth retardation.  Intelligence usually normal odema of hands and felt in neonate and infertility.

11. Renal Anomalies – Like horseshoe kidney.

            Double pelvis may be noticed in ultrasonography in some children with turner syndrome.

·        Mental retardation may be present in some of the patients.

·        The ovaries degenerate with age and they are infertile

Diagnosis

1.       Sometimes takes place later when puberty does not occur.

2.      Turner syndrome may be suspected in pregnancy during on ultra sound test.  This can be confirmed by prenatal testing.

3.      Aminiocentesis was performed at 18 weeks.

 

Medical Management

1.      Cyclical oestrogen therapy at the time of normal puberty.

2.      Cardiac malformations etc treated in used way.

3.      Plastic surgery for webbed neck may be indicated.

4.      Psychological support often required for the problems of small stature infertility etc.

  Complications

            The risk of congenital heart defects such as;

·        Bicuspid aortic valves

·        Aortic co-arctation

·        Valves abnormalities

·        Septal defect is increased

Summary:

            The Turner cause is a missing or incomplete x chromosome. Girls who have it are short and their ovaries don’t work properly. Most women with Turner syndrome are infertile.