Single-gene disorders Flashcards
In 1902, Archibald Garrod presented his studies on ___, a rare condition in w/c patients have urine that darkens on standing & arthritis.
alkaptonuria
Archibald Garrod found that three of 11 sets of parents of patients affected by alkaptonuria are blood relatives &, in collaboration w/ Bateson, proposed that this disease was a ____ w/ affected persons ____ for the underactive gene.
Mendelian recessive trait; homozygous
Alkaptonuria is a rare genetic metabolic disorder characterized by the accumulation of ____ in the body.
homogentisic acid
Individuals affected by alkaptonura lack enough functional levels of the enzyme ____ required to breakdown homogentisic acid
homogentisate 1,2 dioxygenase
This was the first disease to be interpreted as a single-gene trait.
alkaptonuria
At the present time more than ____ human single - gene traits are known
7,000
This was the first demonstration in any organism that a mutation in a structural gene could produce an altered amino acid sequence.
sickle cell anemia
In 1948, Gibson demonstrated the first enzyme defect in an autosomal recessive condition called ____.
Methaemoglobinemia
What is the associated defective enzyme in methaemoglobin
NADH - dependent methaemoglobin reductase in methaemoglobinaemia
____ is a form of hemoglobin that cannot carry oxygen.
Methaemoglobin
The specific biochemical abnormalities in over 400 inborn errors of metabolism have now been determined, but the ____ is still unknown in many human single - gene disorders.
polypeptide product
The study of what type of gene disorders provided valuable insights into normal physiological mechanisms such as normal metabolic pathways .
single-gene disorders
The first human gene assignment was made by Wilson, who identified the trait for ____ in 1911 & assigned the gene to the ___.
colour blindness; X –chromosome
the first autosomal gene to be assigned was ___ to chromosome ____ in 1967.
thymidine kinase; 17
By 1987, a ____ of all human chromosomes had been developed and this was followed in 1993 by the first ___.
complete linkage map; physical map