Chromosomes are made up of DNA and proteins, they are in the core structure of the cells (nucleus) in your body. Genes are segments of DNA that give instructions to your body to form and function, as well as determine specific traits, such as eye or hair color.
Humans normally have 23 pairs of chromosomes (46 total). Chromosomes divide into 22 autosome pairs and one pair of sex chromosomes (X and Y), which determine whether you are male (XY) or female (XX). You receive one set of chromosomes from each parent to make a pair, hence inheriting genes from both parents.
A carrier is an individual who carries a mutated gene associated with a disease or a trait, while the other gene of the same pair is normal, and can pass on to the next generation.
A carrier does not show or only has mild symptoms of the disease or features of the trait. However, the offspring of carrier(s) is at risk of inheriting a mutated gene from their parents, which would result in having the disease or trait.
When both parents are carriers of the same mutated gene on an autosome, there is a quarter of the chance that the child will inherit the variant gene from both parents and be affected by the mutation.
Female carriers of an X-linked recessive disorder have a normal X chromosome and an abnormal one. Male offspring will be affected if the abnormal copy of the X chromosome from his mother is inherited.
Chromosomal structural rearrangements include balanced translocations, insertions, deletions, duplications, inversion, and complex rearrangements. Some chromosomal structural rearrangements may lead to disorders, while others may not cause health problems.
Balanced translocation is a type of genetic variant where part of one chromosome has moved to another chromosome, usually a different pair. Balanced translocations usually have no apparent effect on an individual, however, the offspring can be affected due to the resulting unbalanced translocation.
Heterozygous refers to having different alleles for a particular trait. Absence of heterozygosity occurs if one of the two alleles is absent or gets lost.
Pre-genetic test assessment service helps the clients understand the hereditary nature, the mode of inheritance, the magnitude of the risk of the disease occurrence within the family, and the means of prevention; so that informed decisions can be made in family planning. The service is provided by trained professionals, who are not necessarily doctors.
Under this Programme, medical professionals will assess your personal and family medical history and verify your eligibility for a blood test, introduce the pros, cons, and accuracy of the screening; explain the meaning and potential influence of the test results, discuss medical information for any follow-up required, and provide psychological support if necessary.
Eligible couples with high risks will be provided with free pre-genetic test assessment service, genetic test(s) may be provided according to the couple’s conditions. The test(s) will identify whether you and/or your partner are carriers. With the information, you may better plan and prepare your pregnancy to reduce the chance of getting certain diseases for the next generation.
For details of the eligibility criteria, please click here. Our medical professionals have the rights of the final decision on your eligibility.
Generally, genetic carrier screening has little physical risk, the collection of blood specimen may cause minor discomfort, such as pain, bleeding, bruising, and a very slight chance of infection at the needle puncture site.
Other risks involve the emotional, social, or financial consequences of the test results. In the pre-genetic test assessment process, the benefits, risks, and limitations of the test will be explained in detail. It is important to understand these factors before making any decision.
This Programme is free of charge but only open to eligible people. The test(s), pre-genetic test assessment session(s), and follow-up services are free.
Carrier Screening can be performed before having children. Having Carrier Screening before pregnancy gives you a greater range of options and more time to make decisions.
If Carrier Screening indicates you and your partner are carriers of the same disorder(s) before pregnancy, you have several options:
You can get pregnant and have prenatal diagnostic tests to see if the fetus has the disorder.
You can choose to use assisted reproductive technologies to reduce the risk of having a baby with the disorder.
You may choose not to get pregnant or adopt a child.
Carrier Screening detects known disease-causing mutations on the Carrier Screening panel. It is unable to detect all disease-causing mutations for each disease or all known genetic disorders. A normal test result does not guarantee a baby is born healthy.
Only a brief assessment will be conducted through the phone call. During the first appointment, your eligibility will be verified. If you are qualified for participating in the Programme, you will receive a free pre-test genetic assessment service, and your blood specimen may be collected for the test as assessed by medical professionals.
Genetic carrier screening detects known disease-causing mutations on the Carrier Screening panel. It is unable to detect all disease-causing mutations for each disease or all known genetic disorders. A normal test result does not guarantee zero chance of mutations or risk of disorder, or a baby is born healthy.
Other pre-pregnancy check-ups and prenatal tests focus on different disorders / conditions, you still need to attend all the testing suggested by medical professionals even if you have negative results.
You are required to be a holder of Hong Kong Identity Card, including permanent identity cards, issued under the Registration of Persons Ordinance (Chapter 177).
You are also required to provide a local mobile phone number, and present the original Hong Kong Identity Card for verification purpose.
You will be contacted through email, phone call (with the phone number: 2919 7733), and WhatsApp message.
Please make sure the contact information in your application form is accurate, the email address is available and active, the phone number is a local one and reachable by phone call as well as WhatsApp.
Yes. Your specimen and information will be provided to CUHK, FPAHK will only use your personal particulars for communication purpose and handling applications and follow-ups in relation to the Programme.
The provision of personal data is voluntary and it will be used by The Family Planning Association of Hong Kong (FPAHK) and The Chinese University of Hong Kong — Baylor College of Medicine Joint Centre for Medical Genetics (CUHK) for the following purposes:
Communication
Handling applications and enquiries, providing services and other follow-ups
Teaching, education, statistical, research and data analysis purposes
Apart from the above usage, all personal data will be kept confidential and handled strictly in accordance with applicable laws. Unless permitted or required by law, all personal data will not be disclosed or transferred to any third parties without your prior consent. FPAHK and CUHK will only retain personal information for so long as it is necessary for the fulfillment of the purpose (including any directly related purpose) for which the data is collected. When the personal information that we collect is no longer required, we will destroy or delete it in a secure manner. You have a right to access and correction with respect to personal data as provided for in sections 18 and 22 and Principle 6 of Schedule 1 of the Personal Data (Privacy) Ordinance. If you wish to access and correct your personal, please contact us through email at jcgcs@famplan.org.hk.
