Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

RCPCH TAS/ AKP > Genetics > Flashcards

Genetics Flashcards

1
Q

Genetics and presentation of Russell-Silver Syndrome

A

Imprinting disorder. Maternal uniparental disomy Ch. 7. Reciprocal Beckwith-Wiedeman. Inherited from Father.
- Growth restriction
- Asymmetrical height
- Thin
- Triangular face
- Clinodactyly (curved)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Genetics and presentation of Turner’s Syndrome

A

45, XO
- Short
- Short 4/5th metacarpal
- CHD - Coarctation of aorta
- Cubitus valgus (arm bend out)
- Micrognathia
- Neck webbing
- Low hairline
- Wide spaced nipples, shield chest
- Renal (horseshoe)/ ear anomalies
- Infertility
- Lymphoedema as baby / hydrops

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Management Turner’s

A

12-15y GH / oestrogen
Vit D / calcium - prevent OP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Genetics and presentation of Noonan’s Syndrome

A

Autosomal dominant condition affecting RAS / MAPK
- Short, webbed neck (look similar to Turner’s)
- Scoliosis
- Low set ears, hypertelorism
- CHD - RV outflow obstruction. pulmonary stenosis, hypertrophic cardiomyopathy
- Pectus excavatum
- Mild LD
- Oedema dorsum of foot.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Genetics and presentation of achondroplasia

A

Autosomal dominant. Mutation FGFR3 (inhibits cartilege and bone)
Shortened proximal long bones
Disproportionate sitting / standing height
Large head / frontal bossing /flat nasal bridge

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Genetics and presentation of Klinefelter’s syndrome

A

47, XXY
Additional SHOX gene. Tall stature
Gynaecomastia
Female pattern hair
Broad hips
High pitched voice
Female distribution of fat
GDD / LD
Usually infertile

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Management Klinefelter’s

A

12y - Testosterone replacement –> secondary sexual characteristics, improved behaviour

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Genetics and presentation of Sotos syndrome

A

Mutation NSD1 gene
LD
Large head
Facial features

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Genetics and presentation of Beckwith-Wiedemann syndrome

A

Ch11p15 (growth regulatory region). Imprinting disorder. 50% due to reduced methylation.
Reciprocal to Russell-Silver. Inherited from mother.
Large tongue, coarse facial features
Ear creases
Umbilical hernia
Neonatal hypoglycaemia
NB monitoring renal Wilm’s and hepatic tumours

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What can karyotyping test for?

A

Structural abnormalities in chromosomes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What can array CGH (microarray) test for?

A

Chromosome copy number variations, can look for microdeletions and duplications (not balanced eg Translocation)
Large DDx eg LD

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What does FISH look for?

A

Copy number variants and structural rearrangment - follow up array detected abnrormalities

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What can quantitive fluorescent PCR look for?

A

Rapid aneuploidy testing, follow up array detected abnormalities

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is Mosaicism?

A

2 cell lines with diff. no. of chromosomes –> milder

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Mechanism of genetic changes in trisomies?

A

Most meiotic non-dysjunction (mostly maternal)
Unbalanced translocation
Mosaicism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Presentation of Patau

A

LBW
Cardiac - ASD, VSD, PDA, dextrocardia
Facial abnormalities eg cleft
Neuro
Omphalocoele
Polydactyly
Rocker bottom feet

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Presentation of Edward Syndrome

A

Most due to meiotic non-dysjunction
Facies - low set ears, prominent occiput
Flexed, overlapping fingers
Rockerbottom feet, hammer toes
IUGR
Cardiac - ASD, VSD, coarctation
Renal agenesis
Neuro

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Clinical features of Down’s syndrome

A

IUG
Hypotonia
Upslanting palpebral fissures
Brachycephaly
Low set ears
Flat nasal bridge
Large protruding tongue
Single palmar crease
Brushfield spots
Sandal gap
Duodenal atresia
AVSD

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Elements of combined screening test

A

10-14 weeks
Nuchal translucency
High beta-HCG
Low PAPP-A

20
Q

Elements of quadruple test

A

Beta-HCG - high
Inhibin-A - high
AFP - low
Oestriol - low

21
Q

When can invasive testing be done in pregnancy?

A

CVS 10-15 weeks
Amnio 15-20 weeks
Both 1% risk miscarriage

22
Q

Genetics and features of Di George Syndrome

A

22q11 deletion. Dominant. Usually de novo.
- Facial - long face, folded ears, narrow palpebral fissures, cleft
- Cardiac - TOF, truncus arteriosus, interrupted arch
- Hypocalcaemia, deficiency T cells (thymic hypoplasia)
- Renal tract anomalies
- LD / DD

23
Q

Genetics and features of William’s syndrome

A

7q11.23 deletion (elastin gene). De novo.
- Neonate: poor feeding, hypercalcaemia
- Facial - puffy eyes, long philtrum, stellate iris (lacy)
- LD
- Over chatty / friendly
- CHD - supravalvular aortic stenosis

24
Q

What can Sanger Sequencing be used for?

A

Small single gene defects

25
Q

What can targetted PCR / Southern Blotting be used for?

A

Trinucleotide repeats

26
Q

What can next generation sequencing be used for?

A

Sequencing gene / panel / exome / genome

27
Q

Genetics and presentation of Marfan’s

A

Dominant. Mutation FBN1 (fibrillin). Incomplete penetrance.
- Tall, large wing span
- Arachnodactyly
- Pectus excavatum
- Lens dislocation
- Aortic root dilatation

28
Q

Genetics and presentation NF1

A

Dominant. Loss of function NF1 (neurofibromin gene). Dx 2 or more of:
- 6 cafe-au-lait
- 2 neurofibroma
- Axillary / inguinal freckling
- Sphenoid wing dysplasia
- Optic nerve glioma
- 2 Lisch nodules (iris hamartoma)
- 1st degree relative FN1
Other features: renal artery stenosis, scoliosis, malignant neural sheath tumours

29
Q

Genetics and presentation of Tuberous Sclerosis

A

Dominant. Loss of function TSC 1/2 genes
- Cutaneous- Shagreen patches, ash leaf macules
- Prenatal rhabdomyoma
- Pulm / renal involvement

30
Q

Genetics of Cystic Fibrosis

A

Recessive. More W. Europe.
95% mutation to delta-F508 mutation Ch 7.
CFTR protein controls Chloride channels –> affects mucus.

31
Q

Features of CF

A

Frequent LRTI - pseudomonas
Meconium ileus
Malabsorption
Infertility

32
Q

Investigation and management of CF

A

Ix: High chloride on sweat test
DNA
D5 blood spot - high immunoreactive trypsinogen

Tx: ABx
Mucolytics
Creon

33
Q

Genetics and presentation of Fragile-X

A

X-linked recessive,
Triplet repeat in FMRI gene. >200 repeats = Sx.
Presentation: More males, LD, macrocephaly, mitral valve prolapse.
IX: Targeted genetic testing for expansion FMRI gene.

34
Q

Genetics and presentation of Rett Syndrome

A

X-linked dominant (usually lethal in males)
Loss of function MECP2 (specific sequence and copy numbers)
- Severe LD. Initially normal –> regression
- Slow head growth
- Midline hand movement
- Seizures

35
Q

Which is best tissue to test for mitochondrial disorders?

A

Muscles! Most mitochondria
Targeted sequencing, histology and electron microscopy

36
Q

Mechanism for imprinting

A
  • Methylation defect
  • Uniparental disomy - both copies from same parent. Expect offspring to be unaffected.
  • Uniparental deletion - deletion of imprinted region. 50% offspring.
  • Uniparental mutation of imprinted gene. 50% offspring.
37
Q

Genetic testing for imprinting disorders

A

1st line = methylation testing - PCR / MLPA
Micro satellite analysis - uniparental disomy
Microarray / MLPA (small area) - deletion testing
DNA sequencing - Point mutation / mutation of imprinted gene

38
Q

Genetics and presentation of Prader-Willi syndrome

A

Imprinting disorder 15q11 region. Inherited from FATHER. 70% deletion paternal copy.
Presents:
- Hypotonia
- Mild-mod LD
- SGA –> 12-18m obesity
- Hypogonadotrophic hypogonadism
Ix: Methylation testing –> microarray –> uniparental disomy testing

39
Q

Genetics and presentation of Angelman Syndrome

A

Imprinting disorder, 15q11, reciprocal to Prader-Willi.
Inactive UBE3A gene. Inherited from MOTHER.
Presentation:
- Severe LD 6-12m
- Ataxia
- Happy, smiley, hand flapping
- Microcephaly, wide mouth
- Seizures 80%
- Fair skin / hair
- Disordered sleep
IX: Methylation testing –> microarray –> uniparental disomy testing/ UBE3A sequencing

40
Q

Genetics and presentation of MEN2

A

Mutation in RET proto-oncogene. Autosomal dominant.
Associations – phaeochromocytoma, medullary thyroid cancer, parathyroid hyperplasia, adenoma-causing hyperparathyroidism

41
Q

Conditions associated with HLA-B27

A

Ankylosing spondylitis
Reactive arthritis
Anterior uveitis

42
Q

Genetics and presentation of Ehlers-Danlos syndrome

A

Mutation in COL5A1/2 genes –> defective collagen type V –> reduced collagen.
Present:
-Hyper-extensible skin
- Poor wound healing
- Skin fragility
- Joint hypermobility

43
Q

Blood group inheritance

A
  • ABO is controlled by gene with 3 alleles: i (O), IA, IB. One copy received from each parent. IA and IB dominant over i. Only someone with 2 copies of i will be O blood group. Co-dominance, if get IA and IB then will be AB. Eg parents A and B heterozygous –> ¼ chance of having a child with i (O blood group).
  • Rh – If both parents negative, child will be too. If one negative, and one positive, chance for either if heterozygous positive.
44
Q

What is high maternal AFP associated with?

A

Neural Tube Defects
Also: Multiple preg, abdo wall defects, Turner’s IUD

45
Q

What is low maternal AFP associated with?

A

Down’s syndrome

RCPCH TAS/ AKP (20 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions