Mendelian Inheritance Flashcards
What is the pathological basis of hereditary hemochromatosis?
Excess iron deposition in liver, pancreas, heart, and other tissues
What is the chance that two carriers of an autosomal recessive condition will have an affected child?
1/4
What is the most common genetic disease?
Hereditary Hemachromatosis
What are the criteria for diagnosing neurofibromatosis 1?
2 or more of the following: neurofibromas (2+ or plexiform), cafe-au-lait macules, freckling, optic glioma, iris hamartomas, spenoid dysplasia, affected first-degree relative, scoliosis
What gene is mutated leading to neurofibromatosis 1?
Neurofibromin
What mode of inheritance describes inheritance of a gene located on any of the 22 chromosomes other than X/Y?
Autosomal
What is the mode of inheritance for achondroplasia?
Autosomal dominant
What is the mode of inheritance for hereditary hemachromatosis?
Autosomal recessive
What is the mode of inheritance for neurofibromatosis 1?
Autosomal dominant
What are the 3 characteristics of autosomal dominant inheritance?
Direct transmission from affect parent to affected child, no gender bias, approximately a 1-to-1 ratio of affected vs. unaffected offspring of one affected parent
What are the chances of having an unaffected offspring with 2 parents affected with an autosomal dominant condition?
1/4
What is the genotype of individuals affected with autosomal recessive inherited conditions?
Homozygous recessive
What mutation is the basis for sickle cell anemia?
Glu–>Val substitution in b-hemoglobin subunit
What is the mode of inheritance for sickle cell anemia?
Autosomal recessive
What is dominant inheritance?
Conditions that are expressed when just one allele is present
