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  • Genetic disorder is an effect caused by the abnormal genes or chromosomes.
  • Abnormality of genes or chromosomes is due to mutation or inherited disorder.
  • Therefore, genetic disorder may or may not be a heritable disorder.
  • Autosomal disorder means the inherited disorder takes place on autosomal chromosome.
  • There are two types of autosomal disorders:

1. Autosomal dominant

2. Autosomal recessive

  • This type of disorder is also known as single gene disorder.

1. Autosomal Dominant:

If the disorder is autosomal dominant, the abnormal gene of parent can easily expressed into the offspring.


(a) Huntington’s disease: abnormal chromosome 4, due to that nerve and other parts of brain degenerate.


  • Behavioral disturbance
  • Hallucination
  • Irritability
  • Restlessness
  • Moodiness
  • Psychosis
  • Slow uncontrolled movements
  • Disorientation or confusion
  • Loss of memory
  • Speech impairment
  • Anxiety, stress and tension
  • Personality changes

(b) Polycystic kidney disease:


  • Abdominal pain
  • Blood in urine
  • Excessive urination at night
  • Pain in joints
  • Drowsiness
  • Nail abnormality

(c) Familial hypercholesterolemia: abnormal increase in LDL (bad cholesterol)


  • Formation of “xanthomas” means deposition of fatty skin on hands, elbows, knees, ankles and also around the cornea of eye.
  • Deposition of cholesterol in eyelids.
  • Chest pain
  • Coronary artery disease

(d) Neurofibromatosis type I: Tumor of nerve tissue


  • Blindness
  • Pain
  • Convulsions

(e) Hereditary spherocytosis: also known as congenital spherocytic anemia. Sphere shaped RBCs.


  • Fatigue
  • Weakness
  • Irritability
  • Shortness of breath

2. Autosomal Recessive:

An autosomal recessive disorder means presence of two abnormal copies of gene for development of disease.


(a) Sickle cell anemia: abnormal sickle shaped RBC


  • Fatigue
  • Paleness
  • Rapid heart rate
  • Short breathing
  • Jaundice
  • Blindness
  • Lung, bone and urinary infection
  • Ulcer
  • Delay of growth

(b) Cystic fibrosis: production of thick and sticky fluid called mucus in the body, due to abnormal gene.


  • Delayed growth
  • Weight loss
  • Fatigue
  • Nausea
  • Loss of appetite
  • Cough
  • Inflammation of pancreas
  • Infertility
  • Fever

(c) Tay-Sachs Disease: severe disease of nervous system


  • Deafness
  • Blindness
  • Loss of muscle strength
  • Dementia
  • Paralysis
  • Seizures
  • Slow growth
  • Irritability
  • Slow mental growth

(d) Phenylketonuria: Loss the ability for breakdown an amino acid called phenylalanine.


  • Slow mental growth
  • Small size of head than normal size
  • Hyperactivity
  • Tremors
  • Mental retardation
  • Seizures
  • Skin rashes

(e) Glycogen storage disease:


  • Heart failure
  • Renal failure
  • Hemolytic anemia
  • Lactic acidosis
  • Week muscles growth

(f) Galactosemia: Unable to metabolize galactose


  • Amino acids in urine and blood (aminoaciduria)
  • Enlarged liver
  • Hypoglycemia
  • Convulsions
  • Vomiting
  • Irritability
  • Lethargy
  • Jaundice
  • Poor weight gain
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