Genetics and Dysmorphology Flashcards
What are the typical facial features of Down Syndrome?
Round face with flat nasal bridge and short neck
Upslanted palpebral fissures
Epicanthic folds
Brushfield spots in iris
Small mouth with protruding tongue
Small ears
Flat occiput and 3rd fontanelle
What are the limb features of Down syndrome?
Single palmar creases
Incurved and short 5th fingers
Wide “sandal-toe” gap between 1st and 2nd toes
What are the neurological features of Down syndrome?
Hypotonia
What percentage of children with Down syndrome have a congenital heart defect?
30-40%
What are the long term or later medical issues in Down syndrome?
DD
LD
Short stature
Increased susceptibility to infection
Hearing or visual impairments
Increased risk of hypothyroidism (<15%)
Increased risk of leukaemia and solid tumours (<1%)
Increased risk coeliac disease
OSA
Epilepsy
Early-onset Alzheimers
What types of congenital heart defects are most common with Down syndrome?
ASD and AVSD
What are the 3 types of genetic cause for Down syndrome?
Meiotic nondisjunction (94%)
Translocation (5%)
Mosaicism (1%)
What are the presenting features of Edwards syndrome?
LBW
Prominent occiput
Small mouth and chin
Short sternum
Flexed, overlapping fingers
“rocker-bottom” feet
Cardiac and renal malformations
What gut features can present in Down syndrome?
Duodenal atresia
Hirschsprung’s (<1%)
How is Down syndrome diagnosed?
Clinical suspicion
rtPCR or FISH
What are the clinical features of Turner syndrome?
Lymphoedema of hands and feet in the neonate
Spoon shaped nails
Short stature
Neck webbing or thick neck
Wide carrying angle
Widely spaced nipples
Delayed puberty
Infertility
Hypothyroid risk
Renal anomalies common
Pigmented moles
Recurrent OM
Congenital heart defects
What is trisomy 18 better known as?
Edwards syndrome
What is trisomy 13 better known as?
Patau syndrome
What are the presenting features of Patau syndrome?
Structural defect of the brain
Scalp defects
Small eyes
Cleft lip and palate#
Polydactyly
Cardiac and renal malformations
What is the most common congenital heart defect in Turner syndrome?
Coarctation of the aorta
What syndrome is best characterised by the karyotype XO?
Turner syndrome
What is the treatment offered in Turner syndrome?
Growth hormone
Oestrogen replacement to develop secondary sexual characteristics
How is intellect affected in Turner syndrome?
It is often unaffected
Which condition is caused by the 5p microdeletion?
Cri-du-Chat syndrome
What are the clinical features of Klinefelter syndrome?
Infertility (most common presentation)
Hypogonadism and small testes
Gynaecomastia in adolescence
Tall stature
What are the presenting features in Cri du chat syndrome?
High pitched cry in infancy
Hypotonia
Microcephaly
Intellectual disability
What is best described by the karyotype XXY?
Klinefelter syndrome
Which condition is caused by the 22q11.2 microdeletion?
DiGeorge syndrome
How does Williams syndrome present?
Characteristic facies
Transient neonatal hypoglycaemia
Supravalvular aortic stenosis
Mild-mod LD
Short stature
What are the typical features of DiGeorge syndrome?
CATCH
Cardiac abnormality (interrupted aortic arch, truncus arteriosus, TOF)
Abnormal facies
Thymic aplasia
Cleft palate
Hypocalcaemia/hypoparathyroidism
Intellectual disability
Autism/ADHD
Which syndrome is caused by a 7q11 microdeletion?
Williams syndrome
By which form of inheritance is achondroplasia inherited?
AD
By which form of inheritance is familial hypercholesterolaemia (almost always) inherited?
AD
By which form of inheritance is Huntington disease inherited?
AD
By which form of inheritance is Marfan syndrome inherited?
AD
By which form of inheritance is Osteogenesis imperfecta (most forms) inherited?
AD
By which form of inheritance is Neurofibromatosis inherited?
AD
By which form of inheritance is Noonan syndrome inherited?
AD
By which form of inheritance is Tuberous sclerosis inherited?
AD
By which form of inheritance is Otosclerosis inherited?
AD
By which form of inheritance is Polyposis coli inherited?
AD
By which form of inheritance is CAH inherited?
AR
By which form of inheritance is achondroplasia inherited?
AR
By which form of inheritance is CF inherited?
AR
By which form of inheritance is Friedreich Ataxia inherited?
AR
By which form of inheritance is Galactosaemia inherited?
AR
By which form of inheritance is Glygogen storage diseases inherited?
AR
By which form of inheritance is Hurler syndrome inherited?
AR
By which form of inheritance is Oculocutaneous albinism inherited?
AR
By which form of inheritance is PKU inherited?
AR
By which form of inheritance is Sickle cell inherited?
AR