Genetic Disorders: AD and trinucleotide repeats

Question 1

MEN 1 gene and tumors?

Answer 1

• MEN1 gene
• Parathyroid adenomas
• pituitary adenoma
• Pancreatic tumors
• 3 P’s

Question 2

MEN 2A gene and tumors

Answer 2

• RET gene
• Parathyroid adenoma
• Pheochromocytoma
• medullary thyroid cancer
• “PPM”

Question 3

MEN 2B gene and tumors

Answer 3

• RET gene
• Pheochromocytoma
• Medullary thyroid cancer
• Mucosal neuromas
• “PMM”

Question 4

Mutation and clinical presentation of neurofibromatosis type I (von Recklinghausen)

Answer 4

• Mutation on chromosome 17
• Cafe-au-lait spots
• Neural tumors
• Lisch nodules
• Scoliosis

Question 5

mutation and clinical features of neurofibromatosis II?

Answer 5

• chromosome 22
• Bilateral acoustic neuroma (cranial nerve VIII)
• Hearing loss
• tinnitus
• balance problem
• “think alot of 2’s. NF2, Bi, ch. 22”

Question 6

Genetics and clinical features of Tuberous sclerosis?

Answer 6

• Mutation of hamartin and tuberin gene
• Incomplete penetrance
• Facial lesions (adenoma sebaceum)
• Hypopigmented ash-leaf spots
• cortical and retinal hamartomas
• seizures
• intellectual disability
• cardiac rhabdomyomas
• astrocytomas

Question 7

Describe von Hippel-Lindau disease

Answer 7

• Hemangioblastomas of the retina, cerebellum, and medulla
• 50% develop bilateral renal cell carcinoma
• Pheochromocytomas
• Deletion of VHL gene which results in expression of HIF and activation of angiogenic growth factors

Question 8

Describe fragile X syndrome

Answer 8

• X-linked
• mutation of FMR1 gene which codes for FMRP (cytoplasmic protein found in the brain and testes involved in mRNA translation of axons and dendrites
• Intellectual disability
• macro-orchidism
• long face
• large jaw
• everted ears
• mitral valve prolapse

Question 9

Describe Friedreich ataxia

Answer 9

• Autosomal recessive, trinucleotide repeat disorder (GAA)
• Mutation of gene that codes for frataxin (mitochondrial protein involved in iron detoxifying and storage)
• Degeneration of sensory neurons, hypertrophic cardiomyopathy, diabetes mellitus
• Staggering gait, frequent falling, nystagmus, dysarthria, pes cavus, and hammertoes
• Presents in childhood with kyphoscoliosis