Outside genetics help Flashcards
What is chromosome walking?
Chromosome walking is a method involving hybridizing a primer of known sequence to a clone from a randomly constructed genomic library and synthesizing a short complementary strand (called walking along a chromosome). The complementary strand is then sequenced and its end used as the next primer for further walking. In this way the adjacent, previously unknown, region is identified and sequenced. The chromosome is thus systematically sequenced from one end to the other. Chromosome walking is also used to locate specific genes by sequencing the chromosomal segments between markers that flank the gene of interest.
What is FISH technique?
Fluorescence in situ hybridization is more popularly known as FISH technique. It involves hybridization of a fluorescently labeled probe with the complementary target sequence. The most common fluorescent molecules used are fluorescein isothiocyanate, cy5, rhodamine and texas red.
What is chromosome jumping?
Chromosome jumping is a technique of isolating clones from a genomic library that are non-contiguous i.e. lie at distant sites on the chromosomes.
What is DNA fingerprinting?
DNA fingerprinting is a technique of visualization and analysis of sequence(s) specific to an individual. For this researchers use hypervariable locus, that shows variance from individual to individual.
What is DNA footprinting?
DNA footprinting is a method to analyze a given sequence that is bound to a protein of interest.
What is recombinant DNA technology?
Recombinant DNA technology encompasses a wide variety of techniques that are used in cutting, pasting and proliferating recombinant plasmids and phages. It doesn’t specifically refer to a single technique of molecular biology.
What is translocation?
As shown in the image, the mixture of white and red spots indicate translocation between chromosomes #1 and #2. In this situation, a part of chromosome #1 has migrated to chromosome #2. This is a case of non-reciprocal translocation, since only one chromosome has participated in the translocation event. The mutual exchange of chromosomal regions between two chromosomes is referred as reciprocal translocation.
What is Wilson’s disease?
In Wilson’s disease, plasma ceruloplasmin is typically reduced while dialyzable copper concentration is increased.
What is Duchenne’s Muscular Dystrophy?
Serum creatine kinase activity is greatly elevated, at some time, in all types of muscular dystrophy, and especially so in Duchenne’s type. Patients with DMD can show CK levels even up to 50 times the normal value. In progressive muscular dystrophy, enzyme activity in the serum is highest in infancy and childhood (7-10 years of age) and may be elevated long before the disease is clinically apparent. The genetic defects of DMD have been mapped to the short arm of X chromosome (Xp21).
Polymerase chain reaction is a technique of amplifying a specific DNA sequence from a mixture of sequences. First primers are synthesized that have nucleotide sequences complementary to the target DNA. The DNA sample is heated to separate the strands and then cooled to anneal primers followed by elongation of the new DNA strand. Given that you have primers 20 nucleotides in length containing 10 GC base pairs and 10 AT base pairs, what should be the annealing temperature of your PCR reaction?
Annealing temperature depends on the proportion of AT and GC base pairs. For every AT pair we add 2 degrees of annealing temperature and for every GC base pair we add 3 degrees of annealing temperature. Therefore, (20+30=50) the optimum annealing temperature would be 50° C
What is Fabry’s disease?
Fabry’s disease is the most likely diagnosis as deduced from the clinical features and low alpha galactosidase activity.
Fabry’s disease is an X-linked lysosomal storage disorder resulting from alpha galactosidase deficiency. Acroparesthesias (paresthesia of the extremities), angiokeratoma (skin lesions due to superficial capillary telangiectasis), hypohidrosis (decreased perspiration), corneal opacities, gastrointestinal disturbances, and renal insufficiency are commonly seen in patients with Fabry’s disease.
Alpha galactosidase activity in males and DNA analysis in females are used for diagnosing Fabry’s disease. Enzyme replacement therapy is the treatment of choice.
What is Gaucher’s disease?
Gaucher’s disease is an autosomal recessive lysosomal storage disorder resulting from acid beta-glucocerebrosidase deficiency. There are 3 clinical types: Type 1 - Adult or nonneuronopathic form, Type 2 - Infantile or acute neuronopathic form, and Type 3 - Juvenile or Norrbottnian form. Type 1 disease is characterized by splenomegaly, hepatomegaly, bone involvement, and bleeding secondary to thrombocytopenia. Type 2 disease is characterized by failure to thrive, marked hepatosplenomegaly, neurologic deficits, and stridor. Type 3 disease is characterized by bone involvement, organomegaly, and neurologic involvement.
What is Hurler’s syndrome?
Hurler’s syndrome or mucopolysaccharidosis (MPS) type I is an autosomal recessive lysosomal storage disorder attributed to alpha-L-iduronate deficiency characterized by coarse facial features, corneal clouding, intellectual disability, hernias, dysostosis multiplex (abnormalities in development of skeletal cartilage and bone), and hepatosplenomegaly.
What is Zellweger Syndrome?
Zellweger syndrome is an autosomal recessive peroxisome disorder that affects brain development and growth of the myelin sheath. It is characterized by hypotonia, seizures, unusual facial characteristics, intellectual disability, and liver dysfunction.
What is Phenylketonuria?
Phenylketonuria is an autosomal recessive amino acid metabolism disorder resulting from a deficiency of phenylalanine hydroxylase. It is characterized by intellectual disability, ‘mousy’ odor, light pigmentation of skin, eczema, epilepsy, abnormalities of gait and posture, and acquired microcephaly.
