Paediatric Genetics Flashcards
What are the main genetic causes of developmental delay?
1) Chromosomal e.g. Down’s
2) Single Gene e.g. Duchenne
3) MicroDup/Del
4) Polygenic e.g. ASD/ADHD
What 2 diseases are examples of hypergonadotrophic hypogonadism?
1) Turner’s Syndrome 45X
2) Klinefelter’s 47XXY
Name a disease that is an example of hypogonadotropic hypogonadism.
Kallman Syndrome
What are the main S/S of Turner’s syndrome?
1) Delayed puberty
2) Short stature
3) Webbed neck
4) Recurrent otitis media
5) Low posterior hairline
6) CV/renal malformations
What are the main S/S of Klinefelter’s syndrome?
1) Azoospermia (Semen has no sperm)
2) Tall stature
3) Gynaecomastia
4) Reduced pubic hair
5) Testicle size <5ml
What is the PP behind Kallman syndrome?
1) Congenital deficiency of GnRH –> Poor pituitary stimulation
2) No release of FSH/LH causing gonadal secondary failure
What inheritance pattern does Kallman syndrome have?
X Linked Dominant/Recessive
What do 75% of people with Kallman syndrome have?
Anosmia
Name 3 congenital heart problems that are often associated with Turner syndrome.
Coarctation of the aorta.
Aortic stenosis.
Aortic dissection.
Name 3 diseases with AD inheritance.
ADPKD.
HD.
Marfan’s.
Give 3 characteristics of AD inheritance
Vertical transmission.
Male to male.
Every generation affected.
50% chance of inheritance.
Give 3 characteristics of AR inheritance
Both parents must be carriers.
Often only one generation is affected.
2/3 carrier risk for unaffected siblings.
Name 3 diseases with AR inheritance
CF.
Sickle cell.
Haemochromatosis
What is an example of an X linked disease?
Duchenne Muscular Dystrophy (Also Becker)
What are 3 main characteristics of X Linked?
Male > female affected.
No male to male transmission.
50% of daughters are carriers and 50% of sons are affected.
What are the main examples of Non-Mendelian Inheritance?
1) Multifactorial: NT defects
2) Genomic imprinting
3) Gonadal mosaicism
4) Mitochondrial
Define Gonadal Mosaicism
Gonadal mosaicism is when there are two different populations of cells in the gonads. One population is normal and the other is mutated. All gametes from the mutated line are effected.
