Genetic Syndromes Flashcards
What genetic mutation causes Down’s syndrome
3 copies of chromosome 21 - Trisomy 21
Dysmorphic features associated with Down’s
Hypotonia, short neck, brachycephaly, short stature, flattened face and nose, prominent epicanthic folds, upward sloping palprebral fissures, single palmar crease
Complications of Down’s syndrome
Learning disabilities, recurrent otitis media, deafness and eustachian tube abnormalities, visual problems (myopia, strabismus, cataracts), hypothyroidism, cardiac defects, atlantoaxial instability, leukaemia, dementia
Inheritance of Noonan syndrome
Autosomal dominant
Features of Noonan syndrome
Short stature, broad forehead, downward sloping eyes with ptosis, hypertelorism, prominent nasalabial folds, webbed neck, widely spaced nipples and low set ears
Associations with Noonan syndrome
Congenital heart disease, Cryptorchidism (can lead to infertility), learning disabilities, lymphoedema, increased risk of leukaemia and neuroblastoma
Genetic mutation in Turner’s syndrome
Female has single X chromosome
Features of Turner’s syndrome
Short stature, webbed neck, high arching palate, downwards sloping eyes with ptosis, broad chest with widely spaced nipples, cubitus valgus, underdeveloped ovaries with reduced function, late or incomplete puberty, infertile mostly
Conditions associated with Turner’s syndrome
Recurrent otitis media, UTIs, coarctation of the aorta, hypothyroidism, hypertension, obesity, diabetes, osteoporosis, various specific learning disabilities
Management of Turner’s syndrome
GH therapy, oestrogen and progesterone, fertility treatment, monitor complications and conditions
Genetic mutation in Klinefelters
Male has additional X chromosome, and can have more than just one extra X with more severe features
Features of Klinefelters
Taller height, wider hips, gynaecomastia, weaker muscles, small testicles, reduced libido, shyness, infertility, subtle learning difficulties, appear normal untill puberty
Management of Klinefelters
Testosterone injections, advanced IVF techniques, breast reduction surgery, MDT input
What is the genetic mutation in Prader-Willi syndrome
Loss of functional genes on the proximal arm of the chromosome 15 inherited from the father
Features of Prader-Willi syndrome
Constant irritable hunger leading to obesity, poor muscle tone as infant, mild-moderate learning disability, hypogonadism, fairer soften skin prone to bruising, mental health problems, dysmorphic features, narrow forehead, almond shaped eyes, strabismus, thin upper lip, downturned mouth
Management of prader-wili syndrome
GH aims at improving muscle development and body composition, dieticians to stop overeating
What mutation causes Marfan syndrome
Autosomal dominant condition affecting gene responsible for fibrillin leading to abnormal connective tissue
Features of Marfan’s
Tall stature, long neck, limbs and finegrs, hypermobility, high arched palate, pectus carinatum or excavatum, downsloping palpable fissures
Conditions associated with Marfans
Lens discolouration in the eye
Joint dislocation and pain
Scoliosis of spine
Pneumothorax
GORD
mitral valve prolapse
Aortic valve prolapse
Aortic aneurysms
Management of Marfans
Monitor cardiac complications, minimise BP and HR to reduce stress on heart, ARB, beta blockers, physiom ECHO, opthalmology, pregnancy can have serious complications
Genetic mutation in fragile X syndrome
Mutation in FMR1 gene on chromosome X which has role in cognitive brain development
Features of fragile X syndrome
Intellectual disability, delay in speech and language development, long narrow face, large ears, large testicles after puberty, hypermobile joints, ADHD, autism, seizures
What is the genetic mutation in Angelman syndrome
Loss of function in the UBE3A gene, specifically the copy which is inherited from the mother
Features of Angelman syndrome
Delayed development and learning disability, severe delay or absense of speech development, ataxia, fascination with water, happy demenour, innapropriate laughter, hand flapping, abnormal sleep patterns, epilepsy, ADHD, dysmorphic features, microcephaly, fair skin, light hair, blue eyes, wide mouth, widely spaced teeth
What is the genetic mutation in William syndrome
Deletion of one copy of chromosome 7
Features of william syndrome
Broad forehead, starburst eyes, flattened nasal bridge, long philtrum, wide mouth, widely spaced teeth, small chin, very sociable and trusting, mild learning disability
Associated conditions with Wiliam syndrome
Supraventricular aortic stenosis, ADHD, HTN, hypercalacemia
