534
Biomarkers for Genetic Disorders
There are a large number of genetic disorders where biomarkers are used along with
molecular diagnostics for screening and diagnosis. These are described in more details
in the report on biomarkers (Jain 2015a ). A few examples will be described briefl y.
Biomarkers for Down’s Syndrome
Down’s syndrome is a genetic disorder caused by the inheritance of three copies of
the 21st chromosome. It is the most common congenital disorder with impairment
of mental function; a large percentage of these individuals develop Alzheimer’s
disease in the fi fth decade of life. There is some controversy about the best approach
to screening for Down’s syndrome. The competing claims of advocates of different
screening approaches have made it diffi cult for health planners, clinicians, or preg-
nant women to reach a balanced decision about what should be offered, or chosen.
Table 16.1 Mutation detection technologies
Polymerase chain reaction (PCR)-based methods
Amplifi cation of refractory mutation system (ARMS)
Cleavase fragment length polymorphism (CFLP)
Digital genetic analysis (DGA)
Direct dideoxy sequencing (DDS)
Fluorescence-based directed termination PCR
Heteroduplex analysis (HA) and its other versions
Denaturing gradient gel electrophoresis (DGGE)
WAVE system
Multiplex allele-specifi c diagnostic assay (MASDA)
Non-isotopic RNase cleavage assay (NIRCA)
Primer extension dependent isothermal amplifi cation technology
Restriction fragment length polymorphism (RFLP)
Single-strand conformational polymorphism (SSCP)
TaqMan real-time PCR
Non-PCR methods
Arrayed primer extension (APEX)
BEAMing (beads, emulsion, amplifi cation, and magnetics)
Conversion analysis for mutation detection
Enzyme mutation detection (EMD)
Peptide nucleic acid (PNA) technology
Specifi c anchor nucleotide incorporation
Biochip technologies
Haplotype specifi c extraction (HSE)
© Jain PharmaBiotech16 Personalized Management of Genetic Disorders