BRS BIOCHEM EXAM QUESTIONS AND ANSWERS WITH
COMPLETE SOLUTIONS VERIFIED LATEST UPDATE
Structure/Function:
This disorder affects the enzyme lysyl hydroxylase, results in a defect in collagen
synthesis
Ehlers-Danlos syndrome
[A heterogenous group of disorders of collagen synthesis, marked by hyperextensible
joints and skin; inheritance can be autosomal recessive or autosomal dominant, and at
least one type is X-linked recessive]
Structure/Function:
Caused by mutations in the FBN1 gene, leading to the presence of mutant fibrillin
protein in connective tissues
Marfan syndrome
[Inherited as an autosomal dominant syndrome; many patients have cardiovascular
defects, including mitral valve prolapse and cystic medial necrosis, leading to aortic
incompetence and dissecting aortic aneurysms]
,Structure/Function:
A group of disorders involving the α₁ and α₂ chains of collagen usually inherited
as an autosomal dominant trait
Osteogenesis imperfecta
[Sometimes called brittle-bone disease. Younger patients present with multiple
childhood fractures (arousing suspicion of child abuse), and distinctive blue sclera]
Structure/Function:
This autosomal dominant condition is most often a result of mutations in the β-
myosin heavy gene chain, important in generating contractions within the cardiac
myocytes
Familial hypertrophic cardiomyopathy
[This disorder results in a disarray of the contraction apparatus within cardiac muscle
cells, with the development of a thickened muscular wall; it can lead to sudden death
due to arrhythmias in athletes]
Structure/Function:
Most cases are inherited as X-linked dominant mutations in the α₅ chain of
collagen type IV, which is expessed in the affected tissues
,Alport syndrome
[This syndrome is characterized by nephritis, nerve deafness, and cataracts]
Structure/Function:
This disorder results from a frame-shift mutation leading to the complete absence
of a cytoskeletal protein important in maintaining the shape of the contracting
myocyte
Duchenne muscular dystrophy (DMD)
[This debilitating disorder leads to clumsiness, followed by weakness of the girdle
muscles; confinement to a wheelchair occurs by the teens and death due to respiratory
failure by the early 20s]
Structure/Function:
This disorder results from a quantitative deficiency of the cytoskeletal protein
dystrophin
Becker muscular dystrophy (BMD)
[This disorder is much less severe than Duchenne muscular dystrophy, with a later inset
and nearly normal life span]
Structure/Function:
, Deficiency of the cytoskeletal protein spectrin, resulting in cells that are less
deformable and more vulnerable to destruction in the spleen
Hereditary spherocytosis
[This autosomal disorder is the most common inherited cause of hemolytic anemia in
whites and results in spherical RBCs]
Structure/Function:
This autosomal recessive condition results from a defect in microtuble
polymerization, with defects in neutrophil chemotaxis and phagolysosome
formation
Chediak-Higashi syndrome
[Defects in the formation of functional phagolysosomes from the union of lysosomes
with phagosomes (containing opsonized pyogenic bacteria) results in recurrent
infections by such organisms]
Structure/Function:
This family of transcription factors contains the supersecondary structural helix-
turn-helix motif and is important in pattern formation during embryonic
development
Homeobox Proteins
COMPLETE SOLUTIONS VERIFIED LATEST UPDATE
Structure/Function:
This disorder affects the enzyme lysyl hydroxylase, results in a defect in collagen
synthesis
Ehlers-Danlos syndrome
[A heterogenous group of disorders of collagen synthesis, marked by hyperextensible
joints and skin; inheritance can be autosomal recessive or autosomal dominant, and at
least one type is X-linked recessive]
Structure/Function:
Caused by mutations in the FBN1 gene, leading to the presence of mutant fibrillin
protein in connective tissues
Marfan syndrome
[Inherited as an autosomal dominant syndrome; many patients have cardiovascular
defects, including mitral valve prolapse and cystic medial necrosis, leading to aortic
incompetence and dissecting aortic aneurysms]
,Structure/Function:
A group of disorders involving the α₁ and α₂ chains of collagen usually inherited
as an autosomal dominant trait
Osteogenesis imperfecta
[Sometimes called brittle-bone disease. Younger patients present with multiple
childhood fractures (arousing suspicion of child abuse), and distinctive blue sclera]
Structure/Function:
This autosomal dominant condition is most often a result of mutations in the β-
myosin heavy gene chain, important in generating contractions within the cardiac
myocytes
Familial hypertrophic cardiomyopathy
[This disorder results in a disarray of the contraction apparatus within cardiac muscle
cells, with the development of a thickened muscular wall; it can lead to sudden death
due to arrhythmias in athletes]
Structure/Function:
Most cases are inherited as X-linked dominant mutations in the α₅ chain of
collagen type IV, which is expessed in the affected tissues
,Alport syndrome
[This syndrome is characterized by nephritis, nerve deafness, and cataracts]
Structure/Function:
This disorder results from a frame-shift mutation leading to the complete absence
of a cytoskeletal protein important in maintaining the shape of the contracting
myocyte
Duchenne muscular dystrophy (DMD)
[This debilitating disorder leads to clumsiness, followed by weakness of the girdle
muscles; confinement to a wheelchair occurs by the teens and death due to respiratory
failure by the early 20s]
Structure/Function:
This disorder results from a quantitative deficiency of the cytoskeletal protein
dystrophin
Becker muscular dystrophy (BMD)
[This disorder is much less severe than Duchenne muscular dystrophy, with a later inset
and nearly normal life span]
Structure/Function:
, Deficiency of the cytoskeletal protein spectrin, resulting in cells that are less
deformable and more vulnerable to destruction in the spleen
Hereditary spherocytosis
[This autosomal disorder is the most common inherited cause of hemolytic anemia in
whites and results in spherical RBCs]
Structure/Function:
This autosomal recessive condition results from a defect in microtuble
polymerization, with defects in neutrophil chemotaxis and phagolysosome
formation
Chediak-Higashi syndrome
[Defects in the formation of functional phagolysosomes from the union of lysosomes
with phagosomes (containing opsonized pyogenic bacteria) results in recurrent
infections by such organisms]
Structure/Function:
This family of transcription factors contains the supersecondary structural helix-
turn-helix motif and is important in pattern formation during embryonic
development
Homeobox Proteins
