Flashcards in Genetics Deck (218)
What might be the presenting signs of Turner syndrome in an infant?
Short 4th/5th metacarpal bones, wide spaced nipple or lymphedema hands/feet
What are some common facial features of turners syndrome?d
Low hairline, Webbed neck, small mandible, high arched palate and low set ears
How might an adolescent with turners syndrome present ?
Short stature, minimal breast development and primary amenorrhea
What cardiac abnormality is associated with turners syndrome?
Bicuspid aortic valve or coarctation
What are the chances of turners syndrome in a woman with advanced age?
The same as the normal palpitation! A chromosome deletion is not associated with advanced maternal age (only trisomys are increased)
How do you diagnose turners and what test is inadequate ?
Need karyotype - if mosaicism, karyotype may be normal but FISH can detect mosaicism
Buccal smear inaccurate
What is the genetic defect in cri du chat?
Deletion of the short arm of chromosome 5
What is the difference between apert syndrome and crouzon syndrome?
Both have craniosynostosis but only apert presents with syndactyly
What features of noonan syndrome differentiate from Turner syndrome?
Noonan syndrome has pectus excavatum and pulmonic stenosis
Karyotype is normal!!
What is the inheritance of crouzon syndrome?
A child presents with craniosynostosis, prominent forehead, proptosis and a beak nose, what syndrome should you consider?
You are presented with a tall male with small testes who is socially awkward, what should you test for?
Klinefelters - chromosome analysis
Which age group gives birth to the most amount of trisomies?
Women in their 20s
What is the most common abnormality in children with Down syndrome?
If a mother has a full translocation of chromosome 21, what are the chances her child will have Down syndrome?
If a child has trisomy without translocation of chromosome 21, what are the chances the mother will have another chicks with Down syndrome?
1% plus the age related risk
If an infant had a partial translocation of chromosome 21, what are the chances of recurrence based on which parent the defect came from?
The partial translocation has a higher chance of recurrence if it is from the father
What is the age related risk of trisomy 21 in a 22 year old mother?
What is the age related risk of developing Down syndrome in a child born to a 40y/o mother?
Children with Down syndrome are at increased risk for what 4 conditions?
Endocardial cushion defects
What are the signs/symptoms of trisomy 13?
Brain lesions (microcephaly / holoprosencrphaly)
Abnormally low ears
Leukocyte with nuclear projections
Uterus bicornuate or hypoplastic ovaries
What abnormalities exist in the extremities of a patient with Down syndrome?
5th digit dysplasia
Wide gap between 1st and 2nd toe
What syndrome would you consider in a patient with atrial septal defect and upper limb defects including three jointed thumbs?
Holt Oram syndrome
What syndrome should you consider in a child with self mutilation and choreiform movements?
Lesch nyhan syndrome
What lab abnormalities would you find in a child with lesch nyhan?
Elevated uric acid
A patient presents with rocker bottom feet and clenched fists, what syndrome should you consider?
What abnormal facial features would you find in trisomy 18?
Prominent occiput and low set ears
What organs might be found to be abnormal in a child with trisomy 18?
What syndrome should you consider in a child with cafe au lait spots, fibrous dysplasia and precocious puberty?
Mccune Albright syndrome