Genetics Flashcards
(55 cards)
Name 5 autosomal recessive disease
Cystic fibrosis CAH (21 hydroxylase deficiency) Thalassemia Sickle cell anaemia Wilson disease
Name 6 autosomal dominant diseases
ADPKD Huntington’s Neurofibromatosis BRCA gene breast ca Von Willebrand Hereditary spherocytosis
Name 3 x linked recessive diseases
Duchenne
Haemophilia
G6PD
What does autosomal recessive mean
If BOTH parents arriers
25% child affected
50% to be carrier
Def of autosomal dominant
If 1 parent affected -
= 50% chance child to be affected
25% chance grandchild to be affected
Def of x linked recessive
If mother is carrier
50% chance male child is affected
If father affected
0% chance male child affected
100% chance of female carrier
Features of cystic fibrosis
AR mutation in CFTR gene
= cystic fibrosis transmembrane conductance regulator gene
== increased viscosity and thickness of body secretions
Salty skin, finer clubbing
Recurrent reproductive cough - sputum , chest infections
Long term - thick secretions block pancreatic duct - decreased protein and fat absorption - failure to thrive + fat containing stool (steatorrhoea)-DM1 from pancreatic damage
CF in males usually associated with
Congenital absence of Vas Deferens = infertility
Complication of CF early after birth
Meconium ileus
- meconium might no pass due to thickness
Long term complications of Cystic fibrosis
Diabetes
Cirrhosis
Respiratory failure
Bronchiectasis
Dx of cystic fibrosis + neonatal screening
NS - Guthrie test
- heel prick when baby is 7-10 days old
If +ve - confirm by sweat test and genetic testing for CFTR gene
If not dx as neonate
Sweat test , genetic testing for CFTR
Treatment of cystic fibrosis
No cure , ease symptoms
Azithromycin - long term lung infections
Inhaled hypertonic saline/ salbutamol
Lung transplant
Pancreatic enzyme replacement + fat soluble vitamins
Chest physio - short term benefits
Life expectancy in CF
42-50 YO
80% death due to lung problems
Common in Northern European ancestry
Chance of children to be affected in Cystic fibrosis
CF - autosomal recessive
Children -
25% affected
50% carriers
Important association of polycystic kidney disease
Cerebral aneurysm
- if ruptures can cause SAH
Chance of child to be affected with Polycystic kidney disease if 1 parent has the disease
50%
Features of ADPKD
Abdominal/flank/back pain
Hematuria
HTN - common early manifestation
Assoc with cerebral aneurysm
Blood pressure control in ADPKD
ACEi or ARBs
45 XO =
Turners syndrome
Female
Features of turners syndrome
Learning difficulties Infertility - ovarian dysgenesis / ovarian failure - 1ry amennorrhoea Short stature Short webbed neck Widely spaced nipples Impaired pubertal growth Bicuspid aortic valve.
What is NOT a RF for Turner’s syndrome
Advanced maternal age
What is used during childhood of person with turner’s syndrome
Growth hormone -to increase height
Oestrogen replacement therapy - enhance breast and hip development ad prevent osteoporosis
Deletion of some paternal chromosome 15 genes
Prader Willi syndrome
Prader willi syndrome
Features
- neonatal
-childhood
Neo - floppy baby , almond shaped eyes, short extremities, thin upper lip and downturned mouth
Child - excessive eating (hyperphagia), obese and short, learning difficulties, self injurious behaviour, growth abnormality
