FTM Exam 1 Diseases Flashcards
Turner’s Syndrome
A single X chromosome due to a miosis I non-disjunction event. Father contributes no sex chromosomes.
Kleinfelter’s Syndrome
XXY, due to a meiosis I non-disjunction event.
XYY Syndrome
XYY, due to a meiosis II non-disjunction event
Triple X-syndrome
XXX, due to a meiosis II non-disjunction event. However, Barr bodies still form on 2 of the X chromosomes.
Myotonic dystrophy
Autosomal dominant inheritance pattern. DMPK mutation. Caused by aberrant triplet repeats.
Achondroplasia
Autosomal dominant inheritance pattern. FGFR3 mutation. Gain of function mutation.
Neurofibromatosis Type I
Autosomal dominant inheritance pattern. NF-1 mutation (allelic heterogeneity). NF-1 is a tumor suppressor.
Marfan Syndrome
Autosomal dominant inheritance pattern. Fibrillin-1 gene defect-Dominant negative mutation.
Osteogenesis imperfecta
Autosomal dominant inheritance pattern. Mutated collagen gene(s)-COL1A1 or COL1A2. Haploinsufficiency (Type I).
Familial hypercholesterolemia
Autosomal dominant inheritance pattern. LDL receptor or ApoB mutation. Haploinsufficiency.
Huntington’s Disease
Autosomal dominant inheritance pattern. CAG repeats in Huntingtin protein causes aggregation of it in neurons, leading to
Acute Intermittent porphyria
Autosomal dominant inheritance pattern. Enzyme deficiency of porphobilinogen deaminase. Haploinsufficiency.
Cystic Fibrosis
Autosomal recessive inheritance pattern. CFTR Mutation. Exhibits allelic heterogeneity and variable expression.
Sickle Cell Anemia
Autosomal recessive inheritance pattern. Caused by a mutation in Beta-globin gene.
Phenylketonuria
Autosomal recessive inheritance pattern. Caused by a deficiency of phenylalanine hydroxylase.
Tay-Sachs disease
Autosomal recessive inheritance pattern. Caused by a deficiency of hexosaminidase A.
Congenital Deafness
Autosomal recessive inheritance pattern. Multiple genes.
Hemochromatosis
Autosomal recessive inheritance pattern. Mutations in HFE gene, an iron metabolism gene. Allelic heterogeneity and variable expression in each patient.
Alkaptonuria
Autosomal recessive inheritance pattern. Mutation in HGD gene which codes for homogentisate 1,2-dioxygenase.
alpha-1 Antitrypsin Deficiency
Autosomal recessive inheritance pattern. Deficiency in alpha-1 antitrypsin
Xeroderma pigmentosum
Autosomal recessive inheritance pattern. Caused by a mutation in one of many nucleotide excision repair enzymes, meaning no repair mechanism for UV damage.
Severe Combined Immunodeficiency (Adenosine Deaminase Linked)
Autosomal recessive inheritance pattern. Adenosine deaminase deficiency, due to mutation.
Duchenne’s Muscular Dystrophy
X-linked recessive inheritance pattern. Mutation of the dystrophin gene, but milder phenotype. Appears in heterozygous women due to X inactivation and some men.
Becker’s Muscular Dystrophy
X-linked recessive inheritance pattern. Mutation of the dystrophin gene, but a milder phenotype. Appears in heterozygous women due to X inactivation and some men.
Glucose 6-Phosphate DH deficiency
X-linked recessive inheritance pattern. Abnormally low levels of Glucose 6-phosphate dehydrogenase. This predisposes RBCs to oxidative damage due to glutathione.
Hemophilia A and B
X-linked recessive inheritance pattern. Deficiency of clotting factor VIII, resulting in high tendency to bleed.
Lesch-Nyhan Syndrome
X-linked recessive inheritance pattern. Deficiency of hypoxanthine-guanine phosphoribosyl transferase (HGPRT)
Red-Green color blindness
X-linked recessive inheritance pattern. Defect in cone genes on X chromosome
X-Linked SCID
X-linked recessive inheritance pattern. Defect in gamma chain of IL2RG, an interleukin receptor.
Rett Syndrome
X-linked recessive inheritance pattern. Germline mutation in MECP2 gene. Mother would be a germline mosaic.
Incontinentia pigmenti
X-linked dominant inheritance pattern. Germline mutation or affected parent with mutated IKBKG gene.
Vitamin D-resistant Ricket’s
X-linked dominant inheritance pattern. Caused by a mutation in the PHEX gene, which regulates FGF23.
Charcot-Maire-Tooth Disease
Can have either AD, AR or XR inheritance pattern. Exhibits locus heterogeneity, as multiple genes can contribute to CMT.
Familial Breast Cancer
Autosomal recessive inheritance pattern. Usually BRCA1/2 mutations (about 50% of the time), causes HD repair defect.
MELAS
Mitochondrial inheritance pattern. MT-TL1 (a mitochondrial tRNA) mutations cause 80% of cases. NADH DH is other 20%
Leber’s Hereditary Optic Neuropathy
Mitochondrial inheritance pattern. Mutations in MT-ND1, MT-ND4, MT-ND4L, & MT-ND6 cause this disease. These genes code for NADH dehydrogenase subunits for ox. phos.
MERRF
Mitochondrial inheritance pattern. 80% of cases caused by mutation in the mitochondria tRNA-lysine.
Retinitis Pigmentosa
Multiple patterns of inheritance with multiple genes. In class, we talked about ROM1 and peripherin.
Prader-Willi Syndrome
Loss of SNRPN gene function. SNRPN is epigenetically silenced on chromosome 15 in the maternal genome. Thus, inheriting two maternal copies of chromosome 15 or a microdeletion of the paternal chromosome 15 causes PWS.
Angelman Syndrome
Loss of UBE3A gene function. UBE3A is epigenetically silenced on chromosome 15 in the paternal genome. Thus, inheriting two paternal copies of chromosome 15 or a microdeletion of the maternal chromosome 15 causes AS.
Fragile X Syndrome
Caused by a CGG triplet repeat in the FMR1 gene on the X chromosome, which makes X chromosome look “fragile” toward the telomere end of the P arm.
Friedreich’s Ataxia
Autosomal recessive inheritance pattern. Caused by a GAA expansion in an intron of the FXN gene, leading to reduced expression of the mitochondrial metabolism protein frataxin.
DiGeorge Syndrome
Caused by a microdeletion of 22q11.2. Most cases are novo, but if inherited, it’s autosomal dominant.
Purine Nucleoside Phosphorylase Deficiency (PNP Deficiency)
Autosomal recessive inheritance pattern. Caused by PNP mutation. Very rare. Only 33 documented cases in U.S.
Gout
Hyperuricemia, leading to acute arthritic joint inflammation caused by deposition of uric acid crystals.
Orotic Aciduria (Pyramidine Synthesis Pathway)
UMP Synthase deficiency, leading to a buildup of orotate.
Burkitt’s Lymphoma
Translocation of cMyc to antibody promoter in B cells, causing uncontrolled growth of B cells.
Hutchinson-Gilford Progeria Syndrome is due to:
Lamin A mutation
Describe the nuclear lamina
Thin, sheet-like meshwork beneath the inner nuclear membrane
-Scaffold for nuclear envelope, chromatin & nuclear pores, Disassembles during mitosis
