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 21 st chromosome

Down Syndrome (Trisomy 21):  A Genetic disorder caused by the presence of all or part of an extra 21 st 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 2 nd toes  Protruding tongue  Flat nasal bridge  White spots on iris  Single flexion furrow of 5 th 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 old with a greater risk

Non-Invasive Procedures Screen Weeks Detection False Description Rate Gestatio Positive n Rate Triple 15-20 75% 8.5% measures the maternal serum (a fetal liver protein), estriol, a Screen pregnancy hormone, and hCG, a pregnancy hormone) [ Quad 15-20 79% 7.5% measures the maternal serum (a fetal liver protein), estriol, a Screen pregnancy hormone, hCG, a pregnancy hormone) , and and high inhibin-Alpha (INHA) AFP/Free 13-22 80% 2.8% This test measures the alpha feto protein, produced by the fetus, beta scan and free beta hCG, produced by the placenta Nuchal 10-13.5 91% 5% Uses ultrasound to measure Nuchal TranslucencyTin addition translucency to the freeBeta hCGand PAPPA /free (pregnancy-associated plasma beta/PAPPA protein A). screen

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 B B BR BR Bb Bb BbRR BbRR b (Brown Eyes) (Brown Eyes) (Black hair) (Black Hair) bR Bb Bb BbRR BbRR b (Brown Eyes) (Brown Eyes) (Black hair) b (Black hair) R 4/4 100% Black 4/4 100% Brown haired offspring 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: Almond shaped eyes caused to 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 2 nd 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/