Medical geneticists specialise in diseases of the karyotype and genotype of a patient.
There is significant overlap with
paediatrics.
This is a
pathology discipline.
Etymology
Latin medicus, medica, medicum = healing, curative, medical
Ancient Greek γένεσις (génesis) = origin
Subspecialties
- Cytogenetics
- Molecular genetics
Responsibilities
- Counselling patients and their relatives about the implications of a diagnosis and the risks of inheritance
- Determining the type and number of chromosomes
- Making prenatal diagnoses
- Predicting the severity of disease from the genotype (e.g. counting gene duplications, microsatellite expansions, etc.)
- Sequencing a particular gene to identify mutations
- Screening for a known DNA sequence (e.g. known gene mutations)
Investigations
- Deletion analysis
- Dosage analysis
- Linkage analysis
- Methylation analysis
- Microsatellite analysis
Screening for known mutations
- Comparative genomic hybridization (CGH)
- Karyotype test
- Fluorescence in situ hybridization (FISH)
- Chemical cleavage of mismatch
- Multiplex ligation-dependent probe amplification (MLPA)
- Next generation sequencing (NGS)
- Oligonucleotide ligation assay
- Polymerase chain reaction (PCR)
- Reverse Transcriptase-Polymerase chain reaction (RT-PCR)
- Southern blot analysis
Identifying unknown mutations
- Chemical cleavage of mismatch
- Denaturing Gradient Gel Electrophoresis (DGGE)
- Heteroduplex analysis
- Multiplex ligation-dependent probe amplification (MLPA)
- Next generation sequencing (NGS)
- Oligonucleotide ligation assay
- Protein truncation test
- Restriction fragment length polymorphism (RFLP)
- Reverse Transcriptase-Polymerase chain reaction (RT-PCR)
- Single Strand Conformational Polymorphism (SSCP)
History taking
The history involves being able to construct an accurate and detailed family tree with all available information.
Physical examination
The physical examination should
be guided by both the presenting problems, and the suspected diagnoses.
Many genetic diseases are strongly associated with a characteristic
phenotype. A
facies is a physical appearance which strongly points to a diagnosis.
