Genetics in clinical practice 2 Flashcards Preview

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Flashcards in Genetics in clinical practice 2 Deck (14)
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1
Q

Types of genetic tests

A

standard chromosome analysis, fluorescent in situ hybridisation (FISH), comparitive genomic hybridisation arraay (Array CGH), single gene testing, next generation sequencing, methylation analysis (imprinting disorders)

2
Q

VACTERL association what

A
Disorder that affects many body systems:
Vertebral
Anal atresis
Cardiac
Tracheo-oesophageal atresia, phistula
Renal abnormalities
Limb (radial ray defect)
3
Q

Aneuploidy and polyploidies define

A

Aneuploidy-(chromosome number not dicisible by 23)

Polyploidy–multiple sets of 23 chromosomes

4
Q

Aneuploidy what is it caused by

A

Non disjunction during meiosis so that gamete has one more or less chromosome->gamete fusion would cause 1 more c’some (trisomy) or 1 less c’some (monosomy)

5
Q

Which chromosomes are wrong in Down’s and Patau

A

Down’s-trisomy 21

Patau-trisomy 13

6
Q

Velocardiofacial syndrome symptom and cause

A

Symptom: CHD, cleft andd/or palate, absent thymus, absent parathyroid glands, dysmorphic features, learning difficulties
Cause: deletion of 22q11.22

7
Q

Comparative genomic hybridisation array what does it do and which conditions is it used for

A

Identifies small genomic imbalances which may have effect on individual’s health+development or confer increased susceptibility to certain conditions: autism, psychiatric disease, congenital abnormalities

8
Q

What can del116p11.2 be detected by

A

this is a microdeletion so aCGH

9
Q

What is single gene testing used for

A

Diagnosis/confirmation of genetic disorders, facilitate management, accurate recurrence rissk, reproductive options (prenatal diagnosis, preimplantation genetic diagnosis), test for at risk relatives

10
Q

What diseases can be diagnosed with single gene testing and describe its symptoms

A

Achondroplasia (FGFR3)-skeletal dysplasia, disproportionaly short limbs+large head circumference
Duchenne&Becker muscular dystrophy-both same gene but Becker better prognosis

11
Q

What does genetic diagnosis help with

A
Confirmation of clinical diagnosis
reduces need for other investigations
may help prognostication
Recurrence risk
Informed choice in future prengancies
Presymptomatic testing
gene based therapiess
12
Q

What kind of risk figures does genetic counselling provide

A

risk figure for adult onset condition, offspring risk, family members’ risk

13
Q

What is required for accurate estimation of risk

A

confirmation of the diagnosis, accurate family tree

14
Q

Hardy weinberg rules

A

p+q=1

p^2+q^2+2pq=1