Genomics 101

Genetics … genomics, what’s the difference?

It’s in the Genes

Genetics is the study of the genes that are related to health and disease.
Genomics is the study of the sum total of an organism’s DNA that include genes and intergenic regions.

Genetic Inheritance of Complex Disorders

Hereditary disease is not as simple as inheriting one gene. Developing a hereditary eye disease like keratoconus or glaucoma involves multiple genes and multiple variables including environmental factors and epigenetics. (Epigenetics is the study of how the environment and behavioral factors can affect genes.)

For support on these complex topics, Avellino offers genetic counseling for providers and patients receiving the results of our AvaGen™ genetic test.

Types of Genetic Disorder

In Monogenic Disease, one or more genetic mutations may cause the disease to develop. In Polygenic Disease, multiple causative genes are present and each one has a minor contributing effect to the manifestation of the disease. An individual’s lifestyle (e.g., diet, exercise, or environment) can also play a role in developing this disease.

Avellino’s Processes and Polygenetic Risk Scores – Genetic Testing for Inherited Eye Disease

For Monogenic Diseases:

Avellino uses next-generation sequencing techniques and genome microarray analysis to create gene sequencing panels of a patient’s test sample. Avellino’s Variant Assessment Team carefully assesses each new variant that is seen in a patient’s disease causative genes. This allows us to analyze, interpret, and report the patient’s predisposition to the disease by an extensive search of several clinical and research databases such as ClinVar, OMIM, Gene Reviews, HGMD (Human Gene Mutation Database), PubMed, Gnomad, UniProt, and GeneCards.

For Polygenic Diseases:

Avellino uses complex statistical analytical methods during test development to derive a polygenic risk scoring (PRS) system that predicts the disease risk. Internal case-control studies validate the significance of published disease-associated genetic variants (SNPs) in independent cohorts and the results obtained are used in building optimal and proprietary disease risk prediction models and genetic variant database.

At Avellino, we are studying polygenic diseases of the eye, including keratoconus and glaucoma, as well as monogenic diseases of the eye such as corneal dystrophies.

Genomic Variation

From the efforts of the Human Genome Project and subsequent research, we know while every individual is unique, at the genome level we are about 99.9% the same! The remaining 0.1% may seem small, but in actuality this percentage is what makes one person different from another, including our health. These variations in genomes is the reason why one person may be at risk for glaucoma, for example, while another person may not be.

A somatic variation is one that occurs after birth, while a person is born with germline variants. Both, however, are biomarkers.

The most common type of genomic variant is referred to as a single nucleotide polymorphism (SNP), pronounced “snip.” There is approximately one SNP for every 300 nucleotides, meaning a person can have an average of 10 million SNPs in their genome.

Genetic Counseling

Hereditary eye diseases, monogenic or polygenic, are complex. Understanding individual risk shouldn’t be.

While genetic testing is quite common, such as prenatal and newborn genetic screenings or predictive testing for certain cancers, genetic testing for inherited eye disease is less so—and it can be difficult to understand the implications of the results.

Through Avellino, patients or providers can schedule a session with a genetic counselor to review the results of the genetic testing along with relevant family history information.

What’s more, we make it easy to gather all the relevant family history data through a simple app. And if someone is not sure what condition his late uncle had (as an example), he can invite family members to add information directly through the same app. He retains the power to accept or decline the additional information before it’s added to his history.

This data enriches testing, results, and reporting, and it’s part of what makes our precision health services accurate and highly actionable by healthcare professionals and patients.

Future Tools to Enhance Disease Detection and Broaden Avellino’s Pipeline Products

We never stop discovering. Our continuous research uses the latest information available in the literature and Avellino’s own genetic data and genetic variant database to enhance and improve the detection of genetic diseases so we can continue to advance precision medicine and help improve lives.


For our work utilizing CRISPR, we are currently pursuing two separate paths toward a gene therapy solution to corneal disease. Both of our programs are in flight via our partnership with Ulster University in the UK, where the team is currently focused on validating our discoveries and data on bench and animal models.

Our siRNA (small interfering RNA) program is designed to use “silencing RNA” via a topical treatment for corneal disease. Our CRISPR gene editing program is using a proprietary method to ‘knock out’ mutant variants related to corneal disease as a means to reduce/eliminate off-target effects.