The non-organ system diseases Flashcards
What is the genetic defect in Fragile X syndrome
Defect affecting methylation and expression of FMRI gene
Fragile X syndrome is the __ most common cause of genetic intellectual disability
2nd (after down syndrome)
What are the clinical findings in Fragile X syndrome?
Post pubertal macroorchidism, long face with large jaw, large everted ears, autism, mitral valve prolapse (Extra large testes, jaw, ears)
What is the mode of inheritance of fragile X syndrome?
X-linked trinucleotide repeat disorder (CGG)
What trinucleotide repeat expansion involves CTG nucleotides and the DMPK gene?
Myotonic Type 1 Dystrophy
What is abnormally expressed in Myotonic Type 1 Dystrophy? What does this lead to?
Myotonin protein kinase - Myotonia, muscle wasting, frontal balding, cataracts, testicular atrophy, and arrhythmia
What disease is caused by a meiotic nondisjunction of homologous chormosomes associated with advanced maternal age?
Down Syndrome (Trisomy 21)
What is the genetic defect in Cri-du-chat syndrome?
Congenital microdeletion of short arm of chromosome 5
What is the genetic defect in Williams syndrome?
Congenital microdeletion of long arm of chromosome 7 (deleted region includes elastin gene)
What is the clinical presentation of Williams syndrome?
“Elfin” facies, intellectual disability, hypercalcemia (increased sensitivity to Vitamin D), well developed verbal skills, extreme friendliness with strangers
What is CATCH-22 in DiGeorge syndrome?
Cleft palate, Abnormal facies, Thymic aplasia (T cell deficiency), Cardiac defects, Hypocalcemia - Microdeletion at 22q11
What deficiency leads to phenlketonuria?
Due to decreased phenylalanine or decreased tetrahydrobiopterin cofactor
What findings are associated with Von Hippel Lindau disease?
Cerebellar hemangioblastomas
Clear cell renal carcinoma
Pheochromocytoma
