genetic diseases Flashcards
Fabry disease
X linked
Myotonic dystrophy inheritcance
autosomal dominant triplet repeat expansion disorder
Genetic anticipation
What is the chance of a daughter of an affected male inheriting the gene
100% - all fathers pass condition to daughters
When are large expansions of triple repeat diseases more likely
More likely if mother is affected
Manifest w foetal akinesia and polyhydraminos
What is oncogensis
Swtiching on a normal allele by activating mutation
Which sex chromosome aneuploidies are likely to be incompatible with life
45 Y
45 X - tunrers syndrome
Often also fails early but more likely ot survive to term
Exampels of chromosome microdeletion conditions
Williams syndrome
Prader willi
Angelman
Smith Magenis
Inheritance of ehlers dhnalos
Range of different genes - collagen biosythnthesis and turnover
Autosomal dominant
What causes marfan syndrome
Autosomal dominant disorder caused by pathogenic variation in FBN1 gene
What is MSI testing
Somatic test of tumour tissue
What is Turners syndrome
45 XO karyotype
Features of turners syndrome
webbed neck
broad shield chest with widely spaced nipples
cubitus valgus
short fourth metacarpal
lymphoedema of the extremities in the neonate - particularly the feet
low set ears in up to 80%
low hairline
hypoplastic nails
hypertension, which may be idiopathic or may be secondary to coarctation of the aorta
Marfans syndrome features
tall stature, long limbs, scoliosis, chest deformities, joint hypermobility, and eye problems such as lens dislocation and myopia
What is the most important complication of marfans syndrome
Aortic aneurysma nd dissection
Cardiovascular manifestations of marfans
Aortic root dilatiation
Mitral valve prolapse
Tricuspid valve prolapse
Aortic rgurgitation
Pulmonary artery dilatation
MSK manifestations of marfans
Arachnodactyly
Dolichostenomelia
Pectus deformities
Scoliosis
Joint hypermobility
Pes planus - flat feet
Protrusio acetabuli - medial displacement of hup
Ocular and resp manifestations of marfans ydnreom
Ectopia lentis - disclocation or subluxation of lens - hallmark
Myopia
Retinal detahcment
Galucoma and cataracts
Spontaneous oneymothorac
Restrictive lung disease - scolisois etc
What is ehler-dhanlos syndroem
Autosomal dominant connective tissue disorder mostly affecting type III collagen
Features of ehler dhanlos
Elastic fragile skin
Joint hypermobility and recurrent dislocation
Easy brusing
Aortic regurgitation, mitral valv prolapse and aortic dissection
Subarrachnoid haemorrhage
Angioid retinal streaks
