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Patient Care Services - Woman and Child - Maternal - Genetics Clinic


Please note that upon arrival at the hospital, patients must first register in Central Registration located in C-Wing, Level 2, Room 2246


The Genetics Clinic offers prenatal and medical genetics services in the areas of: assessment, diagnosis, and counseling to individuals of all ages and their families.


Genetics is the study of genes and chromosomes. Genes are the genetic material that determines how we grow and function. Traits such as blood type, hair and eye colour for example are determined by our genes.


All individuals receive half of their genes from their father and half from their mother. If either parent or both parents have a change in a gene, it may be passed on to their children.


Some genetic problems are identified at birth. Others may appear later in childhood or even as an adult.


Various factors can cause birth defects, including certain drugs or alcohol, nicotine, some infections and some medications.


Reasons for Referral
Various reasons for referral to a genetics clinic are outlined below. Each referral would involve counseling and/or testing where available, appropriate and desired by the individuals referred. In some situations the appointment is more of an information session and testing may not be recommended or desired. Any testing is with the consent of the individuals referred or their guardian.


Diagnostic Testing
Diagnostic testing is used to confirm or rule out a known or suspected genetic disorder in a symptomatic individual. For example; infants and children with developmental delay, dysmorphic features or congenital anomalies may be referred for investigation. Adults or children with neurological, muscular or metabolic conditions could be referred to confirm a clinical diagnosis or to attempt to find a diagnosis.


Predictive Testing
Predictive testing is offered to asymptomatic individuals with a family history of a genetic disorder. Predictive testing is of two types: presymptomatic (eventual development of symptoms is certain when the gene mutation is present e.g. Huntington’s disease) and predispositional (eventual development of symptoms is likely but not certain when the gene mutation is present, e.g. breast cancer).


Prenatal Testing
Prenatal testing is performed during a pregnancy to assess the health status of a fetus. Prenatal diagnostic tests are offered when there is an increased risk of having a child with a genetic condition due to maternal age, family history, ethnicity, or suggestive multiple marker screening results such as Second Trimester Screening, Integrated Prenatal Screening (IPS) or fetal ultrasound examination. Routine prenatal diagnostic procedures are amniocentesis and chorionic villus sampling (CVS).


Carrier Testing
Carrier testing is performed to identify individuals who have a gene mutation for a disorder inherited in an autosomal recessive or X-linked recessive manner. Carriers usually do not themselves have symptoms related to the gene mutation. Carrier testing is offered to individuals who have family members with a genetic condition, family members of an identified carrier, and individuals in ethnic or racial groups known to have a higher carrier rate for a particular condition. Some examples would be Sickle cell anemia, thalassemia, cystic fibrosis and Tay Sachs.


Preconception Counselling
Counselling is available for all of the above reasons for couples who are planning a pregnancy and would like to discuss potential risks and testing options before they conceive. In some situations there is a history of recurrent miscarriages (three or more) or fertility concerns that could be investigated from a genetic perspective.


Contact information:

Mackenzie Richmond Hill Hospital
B-Wing, Level 2
10 Trench Street
Richmond Hill, ON
L4C 4Z3
The main office and reception room: #2912. (The clinic is located close to our Tim Horton’s kiosk)
Phone: 905-883-1212 ext. 7579
Fax: 905-883-2052
To refer patients: 
Physicians are asked to fax referrals to the above fax number using the “High Risk Pregnancy and/or Genetics”  form available on our website under “Staff and Physicians,” then “Online Forms” (links also available below) to the above number.  You may also call the above number to obtain a copy of the referral form. 

Visit our referral forms here:

Genetics Clinic Hours

Monday through Friday 8:30 a.m. to 4:30 p.m.

Mackenzie Health / 10 Trench St. Richmond Hill, On. L4C 4Z3 / Richmond Hill Line: 905-883-1212 or Vaughan Line: 905-832-4554 / TTY Service: 905-883-2123