Darcey Fletcher, Aden Assefa, And Eric Apolinario Trisomy: - - PowerPoint PPT Presentation

Darcey Fletcher, Aden Assefa, And Eric Apolinario

“Trisomy”:

Possessing three copies of a particular chromosome instead of the normal two copies.

“21”

The 21st chromosome

Down Syndrome (Trisomy 21):

 A Genetic disorder caused by the presence of all or

part of an extra 21st chromosome.

 Named after John Langdon Down  1 out of 800-1,000 births affected

Karyotype of Trisomy 21:

47, XY, +21

47: Total # of chromosomes (46 is normal) XY: Sex Chromosomes (male) +21: Designates the extra chromosome as 21

Signs/Symptoms of Trisomy 21

 Lower than average cognitive ability (IQ of 35-70)  Single transverse palmer crease (1 instead of 2 creases across

palm(s))

 Almond shaped eyes caused by epicanthic folds of eyelids  Upslanting palpebral fissures  Shorter limbs, neck, and excessive joint laxity  Poor muscle tone  Larger than normal space between big and 2nd toes  Protruding tongue  Flat nasal bridge  White spots on iris  Single flexion furrow of 5th finger  AT HIGHER RISK FOR: congenital heart disease, recurrent ear

infections, obstructive sleep apnea, and thyroid dysfunctions

Parental Screening Parental Screening

 Amniocentesis (invasive)  Chronic Villus Sampling (CVS) (also invasive)  Percutaneous Umbillical Blood Sampling (PUBS)

These procedures are generally performed on women 30 +years

• ld with a greater risk

Non-Invasive Procedures

Screen Weeks Gestatio n

Detection Rate

False Positive Rate

Description

Triple Screen 15-20

75% 8.5%

measures the maternal serum (a fetal liver protein), estriol, a pregnancy hormone, and hCG, a pregnancy hormone)[

Quad Screen 15-20 79% 7.5%

measures the maternal serum (a fetal liver protein), estriol, a pregnancy hormone, hCG, a pregnancy hormone), and and high inhibin-Alpha (INHA)

AFP/Free beta scan 13-22 80% 2.8%

This test measures the alpha feto protein, produced by the fetus, and free beta hCG, produced by the placenta

Nuchal translucency /free beta/PAPPA screen 10-13.5 91% 5%

Uses ultrasound to measure Nuchal TranslucencyTin addition to the freeBeta hCGand PAPPA (pregnancy-associated plasma protein A).

Possible (medical) treatment

  None that will provide a cure

None that will provide a cure

 Kids benefit from medical intervention starting at infancy  Kids will be assigned a team of specialists (cardiologist,

gastroentrenologist, developmental pediatrician etc)

 Kids will benefit from: physical therapy, speech

pathology, occupational therapy, and others to help develop skills as well as possible

  Early Intervention Programs:

Early Intervention Programs:

 Kids are stimulated at an early age with appropriate

activities

 Goal of programs: to help your baby develop motor skills,

language, social skills, and self-help skills

What may my child look like?

Physical characteristics of normal parents:

Parent 1: Parent 2: Parent 1: Parent 2:

Black hair (BBRR) Blonde hair (bbRR)

BB= two dominant alleles for black hair bb= 2 recessive alleles for blonde hair RR= 2 dominant alleles for not red hair RR= 2 dominant alleles for not red hair

Brown eyes (EE) Blue eyes (ee)

EE= two dominant alleles for brown ee= 2 recessive alleles for blue eyes eyes

Punnett Squares

BbRR

(Black hair)

BbRR

(Black Hair)

BbRR

(Black hair)

BbRR

(Black hair)

BR BR bR b R

4/4 100% Black haired offspring

Bb

(Brown Eyes)

Bb

(Brown Eyes)

Bb

(Brown Eyes)

Bb

(Brown Eyes)

B B b b

4/4 100% Brown Eyed offspring

Result: Black hair, Brown eyes

Also with down syndrome Also with down syndrome features including but not limited features including but not limited to to: Almond shaped eyes caused by epicanthic folds of eyelids Upslanting palpebral fissures Shorter limbs, neck, and excessive joint laxity Poor muscle tone Larger than normal space between big and 2nd toes Protruding tongue Flat nasal bridge White spots on iris

What to expect

 Children with down syndrome can generally do what most other children

can do (walking, being toilet trained, etc) but usually do them later than normal children

 Many babies with down syndrome are born with medical problems needing

surgery

 There are special programs beginning in the preschool years to help children

with Down syndrome develop skills as fully as possible

 While there are special work programs designed for adults with Down

syndrome, many people with the disorder can hold regular jobs

 In general, for women under 40 (after having one child with Down

syndrome), the chance of having another baby with Down syndrome is 1 %, but increases with age

 there is no reason to believe that a parent could have done anything to

cause or prevent the birth of their baby with Down syndrome.

 Kids with Down syndrome benefit from loving homes, early intervention,

inclusive education, appropriate medical care and positive public attitudes.

 Life expectancy has increased greatly from 25years in 1980 to 49 years in

2002

Links Used

 http://www.ndsccenter.org/resources/package3.php  http://en.wikipedia.org/wiki/Hair_color  http://www.yale.edu/ynhti/curriculum/units/1982/7/82.

07.06.x.html

 http://en.wikipedia.org/wiki/Down_syndrome  http://www.mayoclinic.com/health/down-

syndrome/DS00182/DSECTION=7

 http://dir.yahoo.com/Health/Diseases_and_Condition

s/Genetic_Disorders/