Genetic Diseases Flashcards
(23 cards)
Trisomy 21: Down Syndrome
Heart: Mitral valve prolapse, malformations of venous inflow, atrial or septal defects
Duodenum: Atresia
Enlarged tongue, open mouth, narrow palate
15x increased risk of leukaemia
Trisomy 18: Edward’s Syndrome
Micrognathia
Rocker bottom feet
Trisomy 13: Patau’s Syndrome
Cleft lip and palate
Rocker bottom feet
Triple test
For diagnosis of trisomy 21
Alpha-fetoprotein down
Unconjugated estriol down
Human chorionic gonadotropin up
Turner’s Syndrome
Female with only 1 X
Primary infertility
Short neck with net webbing
Genitalia is not well developed
Klinefelter Syndrome
Male with extra X, the effects of testosterone are depressed
Feminization features
Treatable
Fragile X syndrome
Amplification of CGG repeats
Long face and prominent ears
Huntington’s Disease
Defect is on Chromosome 4
Behaviour changes
Abnormal and unusual movements
Dementia that slowly gets worse
-affects neural development because of the misfolding of the huntington gene
Disease develops with lesser amount of repeats than in Fragile X
Prader Willi Syndrome
Paternal gene deletion/Maternal disomy
Male portion is imprinted and silenced
Hypotonic muscles
Obesity
Angelman Syndrome
Maternal gene deletion/Paternal disomy
Maternal portion is imprinted and silenced
“Happy Puppet Syndrome”
Hypertonic muscles- ataxia
Marfan Syndrome
Autosomal dominant Defective fibrillin Cardio: Mitral valve prolapse, weak aorta (dissecting aneurysm) Skeleton: Very tall and lean Eyes: Nearsighted, dislocated lenses Palate deformity
Ehlers Danlos Syndrome
Faulty collagen Group of disorder- 6 major types Autosomal dominant, some recessive Joint pain and arthritis Hyperflexibility/hypermobility- joint dislocation because not supported properly Soft "velvety" skin with hyper extensibility, bruises easily, slow and poor wound healing that causes severe scaring Blue sclera Periodontitis
Familial Hypercholesterolemia
Autosomal recessive
Mutatino for LDL receptor on hepatocytes
LDL accumulates in plasma- promotes atherosclerosis, can give rise to periodontitis
Cystic Fibrosis
Most common lethal gene in whites
Defect in cystic fibrosis transmembrane conductance regulator (CFTR), gene on chromosome 7
-Increased mucous viscosity, allows bacteria to thrive
-Salty hypertonic sweat with high chloride, used for diagnosis
-Pancreatic duct plugging and destruction of pancreas, can lead to malabsoprtion of some vitamins that require pancreatic secretions
Prone to nasal polys (involves the dysfunctional mucous?)
Lung infections cause most of the deaths
Alkaptonuira
Lack of homogentistate 1,2-dioxygenase Build up of homogentisic acid (HGA) Manifests after 30 years of age HGA in the urine Urine to turn dark upon standing Bluish-black pigmentation in connective tissue Arthritis of spine and larger joints
Phenylketonuria
Lack phenylalanine hydroxyls
Plasma phenylalanine accumulates
Brain damage
Von Gierkes Disease
Glucose-6-phosphatase deficiency Hepatic form of glycogen storage disease Unable to liberate the glycogen stored in liver Liver becomes enlarged Hypoglycemia- failure to supply glucose
McArdle’s Disease
Muscle phosphorylase missing
Myopathic (muscle) form of glycogen storage disease
Unable to liberate glycogen stored in striated muscle
Muscles are weak and cramp on exercise
Pompe’s Disease
1,4-Glucosidase deficiency
Both muscle and liver unable to liberate glycogen as this enzyme is required in both
Lethal, death usually by age 2- common cause is heart failure as even the cardiac muscle becomes affected
Hepatomegaly
Muscular weakness
Niemann-Pick Disease: Lysosomal storage disease
Deficiency in sphingomyelinase
Sphingomyelin accumulates- macrophages, neurons become foamy
Spleen and bone marrow affected especially
Death by age 5
Gaucher Disease: Lysosomal storage disease
Defective glucocerebrosidase
Glucocerebrosidase accumulates- foamy phagocytes in liver, spleen, bone marrow, brain
Specialized symptom= bone damage, bone marrow is replaced with Gaucher cells
Tay-Sachs Disease: Lysosomal storage disease
Defective hexosaminidase-a
GM2 ganglioside accumulates in neurons in CNS, PNS and retina
Limited to neural tissue
Specialized symtoms= blindness, seizures
Cherry red spot on retina allows early diagnosis
Hurler Syndrome and Hunter Syndrome
Heparan sulphate and Dermatan sulphate storage
Mucopolysaccharidoses- defective degradation of mucopolysaccharide made by fibroblasts
Accumulation leads to coarsening of the skin and facial features
Also called gorgoylism
Shortened life- Hurler more severe
