Applications of human genomics

What is the difference between genetics and genomics?

Genetics focuses on single genes and how traits are inherited, while genomics studies all genes, their interactions, and how the entire genome functions as a system.

What is the scale of the human genome and Y chromosome?

The human genome has ~3 billion base pairs. The Y chromosome spans ~59 million bp with ~150 genes, including the SRY gene (~1.1 kbp) that triggers male sex development.

What distinguishes Mendelian from non-Mendelian disorders?

Mendelian disorders are monogenic—one gene mutation causes disease. They are rare but have clear inheritance. Non-Mendelian (multifactorial) disorders involve many variants and environmental effects.

What genomic tests are used in medicine?

Single-gene tests: detect known variants.

Gene panels: sequence multiple relevant genes.

Whole-Exome Sequencing (WES): all coding regions.

Whole-Genome Sequencing (WGS): all DNA, including regulatory regions.

How does genomics help diagnose rare diseases?

By identifying pathogenic mutations in genes causing monogenic disorders like cystic fibrosis or BRCA-related cancers. WES/WGS improves diagnosis when symptoms overlap or genes are unknown.

Case Study – BRCA and Breast Cancer

BRCA1/2 are tumour-suppressor genes. Pathogenic variants cause a 60–80 % lifetime risk of breast/ovarian cancer. Genomic testing guides predictive screening, prophylactic surgery, and targeted PARP inhibitor therapy.

Case Study – Mila Makovec (Personalised Therapy)

A 6-year-old with CLN7 Batten disease had her mutation discovered by WGS. Scientists designed a custom antisense oligonucleotide drug (“Milasen”) in under a year—proof of personalised genomic medicine.

How does genomics study common diseases?

Via Genome-Wide Association Studies (GWAS), which scan genomes of thousands of people to find variants more frequent in patients than controls. These variants indicate risk loci for conditions like type 2 diabetes or heart disease.

What are polygenic risk scores (PRS)?

PRS combine the effects of many variants identified by GWAS to estimate an individual’s overall genetic predisposition to complex diseases.

What is pharmacogenomics?

It examines how genetic differences (e.g. CYP450 enzyme variants) alter drug metabolism and response. This enables personalised dosing and drug choice to reduce adverse reactions.

What is the NHS Genomic Medicine Service?

Launched in 2018 after the 100,000 Genomes Project, it integrates genomic testing into NHS care—especially for cancer, rare, and infectious diseases—making precision medicine routine in the UK.

What does evolutionary genomics investigate?

It reconstructs human evolution, migration, ancestry, adaptation, and interbreeding events through comparative genome analysis of modern and ancient DNA.

What is gene–culture coevolution?

Interaction between cultural practices and genetic adaptation. Example: lactase persistence (LCT gene) became common in dairy-farming populations due to selection for lactose digestion.

What is adaptive introgression?

Beneficial genes introduced through interbreeding with archaic humans.

Denisovan EPAS1 helps Tibetans survive low oxygen.

Neanderthal TLR alleles improved ancient immunity but increase modern autoimmune risk.

How did Neanderthal DNA influence modern humans?

Svante Pääbo sequenced Neanderthal/Denisovan genomes (Nobel 2022). Modern humans carry immune-related genes from them, including a chromosome 3 haplotype linked to severe COVID-19 identified by GWAS.

What are key applications of genomics in forensics?

DNA profiling using STRs, mitochondrial DNA, and Y-chromosome markers; database matching; DNA phenotyping (HIrisPlex for hair/eye colour); and microbiome forensics using skin/soil microbes.

What major forensic cases used genomics?

Colin Pitchfork (1986): first criminal caught via DNA fingerprinting.

Golden State Killer: traced using genealogy databases.

Romanov Family: mtDNA confirmed royal remains.

9/11 Victims: mtDNA + STRs identified degraded remains.

DNA Exonerations: freed wrongly convicted prisoners.

How is genomics applied in agriculture?

Creates genetically modified and CRISPR-edited crops/animals for higher yield and disease resistance (e.g. Golden Rice). Genomic selection in cattle improves milk yield and resilience.

What are industrial applications of genomics?

Engineered yeast produces human insulin.

Synthetic biology develops biofuels and biodegradable materials.

Microbiome research improves probiotics and digestion.

What is conservation genomics?

Uses DNA analysis to preserve biodiversity, detect inbreeding, and design breeding programmes (e.g. for cheetahs or endangered species).

What is metagenomics and why is it important?

It sequences DNA from environmental samples (soil, water, gut) to identify microbes. Applications include studying the gut microbiome and using bacteria for bioremediation.

What ethical issues arise from genomics?

Concerns include data privacy, potential discrimination, and unequal access. Genetic data could be misused by insurers or employers.

What is the CRISPR babies controversy?

In 2018, CRISPR was used to edit embryos in China, producing “gene-edited babies.” It raised global ethical concerns about germline modification and consent.

What is ancestry bias and equity in genomics?

Most genomic datasets are from European populations, reducing prediction accuracy for others and widening global health inequality.

How does AI relate to genomics and ethics?

AI analyses genomic big data for disease prediction but can introduce bias or privacy risks if datasets lack diversity or protection.