Brainscape's Knowledge GenomeTM

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


See full index

3a Notes AC > Paeds Genetics (breif) > Flashcards

Paeds Genetics (breif) Flashcards

1
Q

Pathophysiology of Down Syndrome

Incidence increases proportionately to maternal age

A
  • 3 copies of chromosome 21: Trisomy21
  • Often caused by meiotic nondisjunction where chromosome 21 fails to separate in meiosis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Signs and Symptoms of Down Syndrome

A
  • Hypotonia
  • Brachycephalpy
  • Short head and statue
  • Prominet Epicanthic folds (eyelid)
  • Palmar crease.
  • duodenal atresia
  • Congential Heart problems (see other card)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Long term complications of down syndrome

Average Life expecrancy is around 60y

A
  • Recurrent otitis media; can have glue ear and conductive hearing loss
  • Visual problems – myopia, strabismus and cataracts
  • Subfertility: males are almost always infertile due to impaired spermatogenesis.
  • Learning disability
  • Alzheimer’s (40%)
  • Leukemia in children
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Cardiac Complications of Downsyndrome

A
  • Multiple cardiac problems may be present
  • Endocardial cushion defect (most common, 40%, also known as atrioventricular septal canal defects)
  • Ventricular septal defect (c. 30%)
  • Secundum atrial septal defect (c. 10%)
  • Tetralogy of Fallot (c. 5%)
  • Isolated patent ductus arteriosus (c. 5%)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Investigations Down Syndrome

A
  • Confirmed by Senior paediatrician then genetic blood testing performed
  • When risk > 1 in 150 the woman is offered aminocentesis or chronic villous sampling - karyotyping of fetal cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Pathophysiology of Klinefelter syndrome

X linked

A
  • Chromosomal abnormality where a male will have an extra X chromosome – gives them 47, XXY.
  • Rarely those with Klinefelter syndrome can have even more X chromosomes i.e. 48, XXXY or 49, XXXXY. These are associated with more severe features.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Signs and Symptoms of Kilinefelter syndrome

Occur after puberty

A
  • Infertility – most common presentation
  • Taller height
  • Wider hips
  • Gynaecomastia
  • Weaker muscles
  • Hypogonadism with smaller testicles
  • Reduced libido
  • Shyness
  • Subtle learning difficulties – particularly speech and language
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Invsetigations and Management Klinfelter’s

A
  • Hormone testing: blood or urine samples can reveal abnormal hormone levels
  • Chromosomal analysis to confirm a diagnosis.
  • Testosterone injections improve many symptoms
  • Advanced IVF techniques have potential to allow fertility
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Complications Klinfelter’s

Normal Life expectancy

A
  • Breast cancer compared with other males but still less than females
  • Osteoporosis
  • Diabetes
  • Anxiety and depression
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Genetic Chromosomal disorder

Pathophysiology of Turner syndrome

in 1/2500 females

A
  • Lack of X chromosome in girls: 45 XO

Early miscarriage in 95% cases.

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

Signs and Symptoms Turner Syndrome

Occurs in Girls

A
  • Short Stature
  • Lymphoedema of the hands and feet (neonates)
  • Webbed neck/thick neck
  • Widely spaced nipples
  • High arching palate
  • Ammenhorrea
  • Infertility
  • Raised Gonadotrophin

Complications: Coarction of Aorta, Recurrent Otitis media & UTSs, Hypothroidism, HTN, LD

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

Investigations and Management of Turner Syndrome.

A
  • Ultrasound antenatalys can see oedema in hands and feet
  • Chronix villus sampling
  • Amniocentesis
  • Growth Hormone for statures
  • Oestrogen and Progesterone for sex features
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Pathophysiology Marfan’s Syndrome

1 in 3000

A
  • Autosomal Dominant Connective tissue disorder
  • Defect in the FBN1 gene on chromosome 15 which creates fibrillin which is important component of connective tissue
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Signs & Symptoms Marfan’s

A
  • Tall stature
  • Long neck and limbs
  • High arching palate
  • Arachnoactyly (longer fingers)
  • Pectus excavatum
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Complications of Marfan’s

Life expectancy 40-50y

A
  • Greatest risk comes from dilation of aortic sinusess, leading to mitral valve prolapse and aortic aneurysms.
  • Scoliosis of > 20 degrees
  • Pneumothroax

Myopia

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

Investigations and Management of Marfan’s

A

Clinical diagnosis made.
* Arm span greater than height
* Can test for arachnodactyly; ask the patient to cross their thumb across palm and if the tip goes past the opposite edge this indicates arachnodactyly
Management
* B Blockers and ACEi to keep BP low and reduce risk to heart

Ghrent criteria also used (looks at heart)

17
Q

Syndromic Form of Diabetes

Pathophysiology Prader Willi Syndrome

opposite to Angelman’s

A
  • Absence of Paternal gene on Chromosome 15 (father)
18
Q

Symptoms Prader Willi

A
  • Constant insatiable hunger that leads to obesity
  • Poor muscle tone as an infant – hypotonia
  • Mild-moderate learning disability
  • Hypogonadism
  • Skin prone to bruising
  • Mental health problems, particularly anxiety
  • Dysmorphic features
  • Narrow forehead , almond shaped eyes, thin upper lip, downturned mouth, strabismus (eyes don’t line up in direction)

NICE recommend GH for some symptoms

19
Q

Pathophysiology Angelmans

opposite to Prader Willi

A

Absence of Maternal gene on Chromosome 15 (mother)

20
Q

Signs & Symptoms Angelmans

are unusual fascination with water, happy demeanour and widely spaced teeth.

A
  • Severe delay or absence of speech development
  • Coordination and balance problems
  • Inappropriate laughter
  • Hand flapping
  • Abnormal sleep problems
  • Microcephaly
  • Fair skin, light hair and blue eyes
  • Wide mouth

Link to Epilepsy

There can be feeding difficulties with this condition. Hyperactivity/ADHD is also a problem in children with this condition. Scoliosis can also occur.

21
Q

Pathophysiology Edward’s Syndrome

Second most common autosomal trisomy after trisomy 21.

Maternal age RF. More commonly affecting Females

A
  • Trisomy of chromosome 18
22
Q

Symptoms Edward’s

A
  • Micrognathia (undersized jaw)
  • Low-set ears
  • Rocker bottom feet
  • Overlapping of fingers

Associated with cardiac and renal malformations.

23
Q

Patau Syndrome

A
  • Trisomy 13
  • Microcephalic, small eyes
  • Cleft lip/palate
  • Polydactyly
  • Scalp lesions

Can be associated with structural defects of the brain and cardiac and renal abnormalities.

24
Q

Pathophysiology Fragile X

Prevalence of learning difficulties in males due to fragile X syndrome is about 1 in 4000. Males are always affected but it can affect females as well – vary in how much they are affected.

A
  • Caused by mutation in the fragile X mental retardation 1 (FMR1) gene on the X chromosome.
  • X-linked condition but unclear if it is recessive or dominant.
25
Q

Symptoms Fragile X

A

Clinical features include:
- Moderate-severe learning difficulty (IQ 20-80; mean 50)
- Macrocephaly
- Macro-orchidism – post pubertal
- Characteristic facies – long face, large everted ears, prominent mandible, broad forehead. This is most evidence in affected adults.

26
Q

Pathophysiology Duchenne Muscular Dystrophy

A
  • X-linked recessive inheritance disorder majority
  • Deletion of the gene for dystrophin – this connects the cytoskeleton of a muscle fibre to the surrounding matrix through the cell membrane
27
Q

Symptoms Duchenne Muscular Dystrophy

A
  • Progressive proximal muscle weakness from 5 years
  • Calf Pseudohypertrophy
  • Gower’s sign: child uses arms to stand up from a squatted position
  • 30% of patients have intellectual impairment

most children cannot walk by the age of 12 years
patients typically survive to around the age of 25-30 years
associated with dilated cardiomyopathy

28
Q

Investigations and management Duchenne Muscular Dystrophy

A
  • Raised creatinine kinase
  • Genetic testing has now replaced muscle biopsy as the way to obtain a definitive diagnosis
  • Management is supportive with Physio

Corticosteroids may help preserve mobility and prevent scoliosis; shown to slow progression of muscle weakness by as much as two years. Creatine supplementation can give a slight improvement in muscle strength.

29
Q

Noonan Syndrome

Often seen as Male Turners

A
  • Defect in a gene on chromosome 12
  • As well as features similar to Turner’s syndrome (webbed neck, widely-spaced nipples, short stature, pectus carinatum and excavatum), a number of characteristic clinical signs may also be seen:
    cardiac: pulmonary valve stenosis
    ptosis
    triangular-shaped face
    low-set ears
    coagulation problems: factor XI deficiency
  • Cryptorchidism
30
Q

Diagnosed using Fish Studies

William Syndrome

Usually the result of random deletion around conception, rather than being inherited from an affected parent.

A

William’s syndrome is an inherited neurodevelopmental disorder caused by a microdeletion on chromosome 7.
* Elfin-like facies
* Characteristic like affect - very friendly and social
* Learning difficulties
* Short stature
* Transient neonatal hypercalcaemia
* Supravalvular aortic stenosis

3a Notes AC (20 decks)

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