Congenital Abnormalities Flashcards
What chromosomal abnormality seen in Down’s?
trisomy 21
How common is Down’s syndrome?
1 in 1000 live births
most common autosomal trisomy
most common genetic cause of learning disability
What are the features of Down’s?
Round Face
Brushfield spots in iris
Flat nasal bridge
Epicanthic folds
Protruding tongue
Flat occiput
Single Palmar crease
Sandal gap between toes
Hypotonia
What are some conditions/diseases associated with Down’s?
endocardial cushion defect (c. 40%, also known as atrioventricular septal canal defects)
ventricular septal defect (c. 30%)
secundum atrial septal defect (c. 10%)
tetralogy of Fallot (c. 5%)
hirsprungs
duodenal stresia
What are some conditions Down’s sufferers are more at risk for?
Alzheimer’s
Epilepsy
Hypothyroid
Coeliac
Cataracs
Conductive hearing loss
Leukaemia
By what modes does the trisomy occur in Down’s?
Non-disjunction
Robertsonian translocation
Mosaicism
What are the odds of a mother with a down’s child to have another?
if <35 = 1 in 100
What chromosomal abnormality seen in Edward’s?
trisomy of chromosome 18
What are the features of Edward’s?
Micrognathia
Low-set ears
Rocker bottom feet
Overlapping of fingers
cardiac and renal
What chromosomal abnormality seen in Patau’s?
features?
T13
Microcephalic
small eyes
Cleft lip/palate
Polydactyly
Scalp lesions
Cardiac and Renal malform
What is the chromosomal abnormality of Patau’s?
trisomy of chromosome 13
What is the chromosomal abnormality seen in Turner’s?
45X, 45XO
How can Turner’s be on antenatal USS?
fetal oedema
cystic hydroma
What are some external features of Turner’s?
short stature
shield chest
widely spaced nipples
webbed neck
high-arched palate
short fourth metacarpal
multiple pigmented naevi
lymphoedema in neonates
What are some long term conditions associated with Turner’s?
bicuspid aortic valve (15%)
coarctation of the aorta (5-10%)
hypothyroid
infertility
crohns
NORMAL INTELECTUAL FUNCTION
acronym for Turners features?
CLOWNS
Cardiac abnorm - bicuspid aortic valve, coarctation of aorta
Lymphoedema
Ovaries not developed
Webbed neck
Nipples widely spaced
Short stature
What is the chromosomal abnormality associated with Klinefelter’s?
47, XXY
What are the features of Klinefelter’s?
infertility
hypogonadism
small testes
puberty may be normal
gynaecomastia
tall
intelligence in normal range
What is the chromosomal abnormality associated with Fragile X?
gap or break in distal part of long arm of X chromosome
x-linked recessive
How does Fragile X present?
depends on number of mutations - anticipation
female carriers have learning difficulties
males - moderate to severe learning difficulty
macrocephaly
macro-orchidism
long face
large ears
What are some long term conditions associated with Fragile X?
mitral valve prolapse
joint laxity
scoliosis
autism
hyperactivity
What is the mutation associated with Noonan syndrome?
autosomal dominant genes
What are the features of Noonan’s?
similar to turners
affects males and females
Webbed neck
Pectus excavatum
Short stature
Short broad nose
Low set ears
What heart disease associated with Noonan’s?
Pulmonary stenosis
What is the chromosomal abnormality associated with William’s?
deletion of genetic material from a specific region of chromosome 7
How does William’s present?
Short stature
Learning difficulties
Friendly, extrovert personality
wide spaced, missing or crooked teeth
What are some conditions associated with William#s?
supravalvuvular aortic stenosis
transient neonatal hypercalcaemia
What are the chromosomal abnormalities associated with Prader-Willi?
mater loss of function from chromosome 15
What are some features of Prader-Willi?
eyes that cross or wander
developmetal delay
hypotonia
hypogonadism
learning difficulty
failure to thrive
obesity (problems with food control)
