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Flashcards in Trinucleotide Repeat Disorders Deck (16)
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1
Q

Which genetic defect is commonly associated with anticipation?

A

Trinucleotide repeat defects.

2
Q

At which point does the fragile X syndrome become a disorder?

A

If there are more than 230 copies of the CGG trinucleotide repeat on the X chromosome.

3
Q

What physical changes occur from fragile X syndrome?

A

Long face, Large mandible, everted ears and enlarged testes.

4
Q

Huntingtons disease is a result of what?

A

A trinucleotide repeat of CAG involving chromosome 4

5
Q

At what repeat level does huntingtons become severe?

A

Affected indiviuals have more than 36 compies of CAG repeats on chromosome 4.

6
Q

Chorea, involuntary movements, and oculomotor abnormalities are all signs of what disease?

A

Huntingtons disease diagnosed by genetic testing.

7
Q

What is Edwards Syndrome?

A

Trisomy 18 causing severe psychomotor and growth retardation with microcephaly, clenched fingers.

Club Foot/Rocker bottom foot

8
Q

What is Patau Syndrome?

A

Trisomy 13

Severe intelectual disabilities
Cleft lip
Very small/poorly developed eyes.
Only 5-10 percent live to survive past first year.

9
Q

What is Turners syndrome?

A

Complete or partial X chromosome monosomy in phenotypic female.

10
Q

What is the frequency of turners syndrome?

A

1/5000

11
Q

What is the clinical hallmark of turners syndrome?

A

Sexual infantilism with primary amenorrhea and sterility with most cases not being discovered until absence of menarche.
Very short women
Short Webbed neck

12
Q

What occurs genetically in Klienfelters syndrome?

A

Extra X chromosome displaying the XXY karyotype.

13
Q

What is the occurence for kleinfelters syndrome?

A

1/1000 in male newborns.

14
Q

Prader Willis and Angelman syndrome both occur on what chromosome?

A

Chromosome 15!

15
Q

What are the clinical findings of Prader-Willi syndrome?

A

Metal retardation, short stature, hypotonia at birth.

Obesity tendency to overeat and hypogonadism.

16
Q

What are the clinical findings of Angelman syndrome?

A

Mental retardation
Wide based gate
Inappropriate laughter