syndromes

• Phenylketonuria

  • Lack enzyme necessary for the normal metabolism of the amino acid phenylalanine to the next product, so it accumulates
  • Low IQ
  • Small head size
  • Hair color
• Marfan syndrome

  • Autosomal dominant mutation 
  • Coding the connective tissue protein fibrillin
  • Needed for the structure of the lens of the eye, bones, lining vessels of aorta
  • Lens dislocation
  • Increased risk of aortic aneurism
  • Lengthened bones in limbs
  • Abe lincoln may have been affected
• Porphyria variegata

  • Can’t adequately metabolize porphyrin component of hemoglobin
  • Accumulation of porphyrin can be seen in red colored urine
  • Builds up in body and braid
  • Causes abdominal pain, muscular weakness, vision issues, fever, insomnia, headaches, convulsion
  • King George III affected
• Tay-Sachs Disease

  • Autosomal recessive trait
  • Abnormal lipid metabolism
  • Deficiency of enzyme  Hexosaminidase A 
  • Lethal lipid metabolism disease
  • Newborns are normal, but after a few months, develop mental retardation, paralysis, blindness, die at 3 yrs
• Lesch-Nyhan syndrome

  • X-linked recessive disease
  • Deficiency of enzyme hypoxanthine-guanine phosphoribosyl-transferase (HGPRT)
  • Nucleic acid metabolism
  • Accumulation of  uric acid in blood and tissues
  • Mental retardation, self mutilation of lips and fingers
  • Exclusively in males, newborns are normal for 6-8 months
• DMD - Duchenne muscular disease

  • Caused by a mutation in the dystrophin gene, located on X chromosome
  • Common in boys (normal for 3-5 years), rarely affects females
• Huntington disease

  • Autosomal dominant disease
  • Occurs between 30-50 yrs
• Klinefelter syndrome

  • Tall, long arms/legs
  • Underdeveloped testes and prostate, no facial hair
  • Phenotypically males, infertile, slight gynecomastia
  • Normal intelligence, slow learner
  • Extra X chromosomes (XXY, XXXY)
• Turner syndrome

  • Phenotypically female
  • 1/2000 births
  • Short, webbed neck, high palate, small jaw, congenital heart and kidney defects, ovarian failure, infertility
  • Normal intelligence, learning disabilities
  • 45 XO
• 47, XXX syndrome

  • Presence of 3 X chromosomes with a normal set of autosomes results in female differentiation
  • Most are normal
  • Other cases, underdeveloped secondary sex characteristics, sterility, mental retardation
• 47, XYY condition

  • Males over 6ft tall
  • Subnormal intelligence