Genetics and Congenital Disease
Inherited conditions, chromosomal disorders and genetic counselling.
- Principles of Inheritance Recognising autosomal, X-linked and mitochondrial pedigree patterns, and the non-Mendelian exceptions - reduced penetrance, anticipation, imprinting and mosaicism - that trip up a simple reading.
- Genetic Counselling and Testing Non-directive counselling, the test to choose for a given clinical question from karyotype to whole genome sequencing, and the consent, confidentiality and child-testing rules that govern them.
- Down Syndrome Recognising trisomy 21, why the mechanism on karyotype - not just the diagnosis - determines recurrence risk, and the lifelong cardiac, endocrine and sensory surveillance schedule that has transformed prognosis.
- Turner Syndrome Recognising 45,X and its mosaic variants from short stature and gonadal dysgenesis, why aortic surveillance is the priority that changes prognosis, and hormone replacement for growth and puberty.
- Klinefelter Syndrome Why this commonest sex chromosome disorder is so often missed until adult infertility investigation, the hypergonadotrophic hypogonadism it causes, and why testosterone replacement must be timed around fertility preservation.
- Marfan Syndrome Applying the revised Ghent criteria rather than relying on habitus alone, why both beta-blockers and losartan slow aortic root dilatation, and the surveillance and surgical thresholds that now normalise life expectancy.
- Ehlers-Danlos Syndrome Scoring hypermobility with the Beighton score, separating hypermobile and classical EDS from the vascular subtype that ruptures arteries and bowel, and why stretching a hypermobile joint is the wrong advice.
- Neurofibromatosis Two separate conditions sharing a name: the seven NF1 diagnostic criteria and why learning difficulty outweighs tumour burden, bilateral vestibular schwannomas in NF2, and spotting malignant transformation.
- Familial Hypercholesterolaemia Why lifelong LDL exposure from a single-gene defect makes QRISK3 invalid, applying the Simon Broome criteria, and how cascade testing turns one diagnosis into a family's worth of prevented heart attacks.
- Hereditary Cancer Syndromes The family history that signals an inherited predisposition, why tumour suppressors are dominant in the pedigree but recessive in the cell, and the surveillance and risk-reducing surgery that follow BRCA, Lynch and FAP.
- Antenatal Genetic Screening Why a screening chance is never a diagnosis, the combined and quadruple test marker patterns, what makes NIPT fail despite 99% detection, and the non-directive counselling that must surround every result.