Paediatric - Genetics Flashcards
How many chromosomes are there in the human body?
46 (22 pairs + 2 sex chromosomes)
What are males and females sex chromosomes?
- Male = XY
- Female = XX
What are the other 44 chromosomes called?
Autosomes
What is genotype vs phenotype?
- Genotype = actual genes we have
- Phenotype = how we express those genes in characteristics
What is an intron vs exon in DNA?
- Intron = non-coding portion of DNA
- Exon = coding portion of DNA
What is the process of creating a gamete known as?
Meiosis
Where does the child inherit the mitochondria from?
The mother!!!
What are the effects when there is a mitochondrial disease (2)?
- Poor production of ATP –> myopathy (abnormal muscle function)
- Can also cause deafness, blindness, epilepsy and diabetes
What is kleinfelters syndrome?
When a male has an extra X chromosome
When do features of kleinfelters usually display?
At puberty
What are the features of kleinfelters (9)?
- Tall
- Wide hips
- Gynaecomastia
- Weaker
- Small testicles
- Reduced libido
- Shyness
- Infertility
- Mild learning difficulties
basically all things feminine
How is kleinfelters managed (4)?
- Testosterone
- IVF
- Breast reduction
- MDT (physio, educational support, etc…)
What conditions is there a slight increased risk of for those with kleinfelters (4)?
- Breast cancer
- Osteoporosis
- Diabetes
- Anxiety/ depression
What is turners syndrome?
A female who has a single X chromosome
When does turners syndrome usually present?
Early childhood/ infancy
What are the 3 key features of Turners syndrome?
- Short
- Webbed neck
- Wide nipples + wide chest
What are the other features of turners syndrome (8)?
Key:
* Short
* Webbed neck
* Broad chest, wide nipples
Others:
* High arch palate
* Downward sloping eyes (-ve canthal tilt/ prey eyes) with ptosis
* Cubitus valgus
* Underdeveloped ovaries + infertility
* Late puberty
What is cubitus valgus?
When elbows are extended they are angled away from the body
What conditions are associated with tuners (8)?
- Recurrent UTIs
- Coarctation of the aorta
- Hypertension
- Hypothyroidism
- Obesity
- Osteoporosis
- Diabetes
- Learning difficulties
How is turners managed (3)?
- Growth hormone
- Oestrogen + progesterone (prevent osteoporosis, regulate menstrual cycle)
- IVF
What are the 3 most common forms of trisomy?
- Downs
- Edwards
- Pataus
What trisomy is downs syndrome?
21
What trisomy is Edward’s syndrome?
18
What trisomy is Patau’s
13
What are the features of downs syndrome (7)?
- Hypotonia
- Short stature
- Short neck
- Upward sloping eyes (+ve canthel tilt/ hunter eyes)
- Flat face + nose
- Brachycephaly (small head + flat back)
- Learning difficulties
What are some complications of downs syndrome (7)?
- Congenital heart defects
- Eustachian tube abnormalities (deafness, otitis media)
- Visual problems (myopia, cataracts)
- Hypothyroidism
- GI problems (atresia, hirschprungs)
- Leukaemia
- Dementia
Who/ what is involved in the management of those with downs syndrome (8)?
- Occupational health
- SALT
- Physio
- Dietician
- Paediatrician
- GP
- Opticians
- Educational support plans
What are some routine follow ups for children with downs syndrome (4)?
- 2 yearly thyroid checks
- Echo (for heart defects)
- Audiometry
- Eye checks
What is the life expectancy of those with downs?
60 years
How common is down syndrome?
1 in 1000
What is the prognosis/life expectancy for Edwards syndrome?
Most don’t live past 1 year and die in first few weeks
What are the features of Edwards syndrome (4)?
- Low birth weight
- Low muscle tone
- Unusual looking face
- Learning disabilities