Turner's Syndrome Flashcards
What is Turner’s syndrome?
It is caused by either the presence of only one sex chromosome (X) or a deletion of the short arm of one of the X chromosomes. Turner’s syndrome is denoted as 45,XO or 45,X
What are clinical features of Turner’s syndrome?
Short stature Neck webbing Spoon-shaped nails Wide spaced nipples Coarctation of the aorta Wide carrying angle Delayed puberty
What conditions develop in Turner’s syndrome?
Infertility due to ovarian dysgenesis Hypothyroidism Renal anomalies Delayed puberty Pigmented moles Recurrent otitis media Normal intellectual function
How is Turner’s syndrome treated?
Growth hormone therapy
Oestrogen replacement for development of secondary sexual characteristics at time of puberty (infertility persists)
What is Klinefelter’s syndrome?
47, XXY
Extra X chromosome in male
What are clinical features of Klinefelter syndrome?
Infertilty Hypogonadism with small testes Pubertal development may appear normal Gynaecomastia in adolescence Tall stature Intelligence in normal range
Examples of autosomal dominant conditions?
Achondroplasia Ehler's Danlos Familial hypercholestrolasemia Huntington disease Marfan syndrome Myotonic Dystrophy Neurofibromatosis Noonan syndrome Osteogenesis imperfeta Otosclerosis Tuberous sclerosis
(more structural)
What is non-penetrance?
Lack of clinical signs of symptoms in an indicidual who has inserted the abnormal gene
Examples of autosomal recessive disorders
Cystic fibrosis Congenital adrenal hyperplasia Friedrich ataxia Galactosaemia Glycogen storage diseases Phenylketonuria Sickle cell disease Thalassaemia
What are examples of X-linked recessive disorders?
Colour blindness (red-green) Duchenne and Becker muscular dystrophies Fragile X sydnorme G6pD deficiency HAemophilia A and B
What is fragile X syndorme?
Trinucleotide repeat expansion disorder
Three nucleotides repeat from 55 to 200 times
Over 200 is full mutation
What are clinical features of fragile X?
Moderate - severe learning difficulty
Macrocephaly
Macroorchidism
Long face
Large everted ears
Prominent mandible
Broad forehead
Mitral valvy prolapse Joint laxity Scoliosis Autism Hyperactivity
How is rail X diagnosed?
Chorionic villus sampling
Amniocentesis
Analysis of number of CGG repeats using restriction endonuclease digestion and Southern blot analysis
What are clinical features of Noonan syndrome?
Characteristic facies Occasional mild learning difficulties Short webbed neck Trident hair line Pectus excavatum Short stature Pulmonary stenosis ASD
Clinical features of William’s syndrome?
Short stature Learning difficulties Friendly, extrovert personality Transient neonatal hypercalcaemia Supravalvular aortic stenosis
