In 1997, scientists first reported the presence of small amounts of cell-free fetal DNA among the circulating cell-free DNA in the mother’s blood as early as four gestational weeks1. The rapid development of next generation sequencing technology makes it possible to detect fetal aneuploidies non-invasively and with high accuracy by analysing the cell-free DNA in the mother’s blood.
Cordlife has partnered with iGene Diagnostics, a Singapore-based molecular diagnostics company, to offer iGene™ in Philippines. Compared with other NIPTs, iGene™ has superior clinical performance and is able to screen with very high accuracy for the presence of common chromosomal abnormalities, including Down Syndrome, Edwards Syndrome and Patau Syndrome.
This simple blood test means less anxiety for an expectant mother, father and the whole family. To date, the availability of the test has significantly reduced the number of invasive diagnostic tests, such as Amniocentesis and Chorionic Villus Sampling, which carry a risk of miscarriage of about 1 in 100.
Before you go through with a NIPT such as iGene™, check with your obstetrician on your eligibility for the test. Early screening and detection of potential conditions enables you to make an informed choice and address your baby’s health needs upon birth.
Individuals with Down Syndrome (Trisomy 21) are characterised by typical facial features such as an oval-shaped face and eyes that slant upwards. Most individual diagnose with Down syndrome will have some degree of learning difficulty, delayed speech development and a delay in motor development.
Approximately 50% of babies with Down syndrome are born with a heart defect and are also at risk of developing other medical conditions.
Although women of any age can have a child with Down syndrome, the chance of having a child with this condition increases with maternal age.
Edwards Syndrome (Trisomy 18) is due to an extra copy of chromosome 18, which is associated with a high rate of miscarriages. Many individuals with trisomy 18 die before birth or within their first month. Only 5-10% of affected children live past their first year, and often have severe intellectual disability or congenital heart defects.
Patau Syndrome (Trisomy 13) is due to an extra copy of chromosome 13, which is associated with a high rate of miscarriages. Many foetuses don’t survive until full-term and are stillborn or spontaneously abort. Infants born with Trisomy 13 usually have severe congenital heart defects and other medical conditions, and survival beyond the first year is rare. Features include slow growth before birth, low birth weight, heart defects, organ malformation, brain and central nervous system abnormalities and craniofacial abnormalities.
(Triple X Syndrome)
Triple X syndrome results from an extra copy of the X chromosome in each of a female's cells.
Females with this condition may be taller than average, but it typically causes no unusual physical features. Most females have normal sexual development and are able to conceive children. There is an associated risk of learning disabilities and delayed development of speech, language and motor skills. Seizures or kidney abnormalities occur in about 10% of affected females.
Most often, Turner syndrome results when one X chromosome is normal and the other X chromosome is missing or altered.
The most common feature of Turner syndrome is short stature, which becomes evident by about age 5. An early loss of ovarian function is also very common. Up to half of affected females are born with a heart defect, complications of which can be life threatening. However, most girls and women with the condition have normal intelligence.
Most often, Klinefelter syndrome is the result of at least one extra copy of the X chromosome in each cell. The condition interferes with sexual development, such as reduced levels of testosterone, which can lead to delayed, or incomplete puberty, breast enlargement, reduced facial and body hair, and infertility. It also causes abnormal functioning of the testes.
Jacob’s syndrome is the result of one extra copy of the Y chromosome in each cell. Although males with this condition may be taller than average, this chromosomal change typically causes no unusual physical features. Most have normal sexual development and are able to father children.
There is an increased risk of learning disabilities and delayed development of speech, language and motor skills. A small percentage of males are diagnosed with autistic spectrum disorders, which are developmental conditions that affect communication and social interaction.
(Cri du Chat Syndrome)
This condition results when a piece of chromosome 5 is missing. Affected infants have a high-pitched cry that sounds like a cat, hence the name Cri-du-chat (cat's cry).
It causes intellectual disability and delayed development, small head size, low birth weight, and weak muscle tone in infancy. Affected individuals also have distinctive facial features, including widely set eyes, low-set ears, a small jaw and a rounded face. Some infants with Cri-du-chat syndrome are born with a heart defect. As they grow, people with cri-du-chat usually have difficulty walking and talking. They may have behavioural problems and severe intellectual disability.
This condition results when a piece of chromosome 1 is missing, and typically causes severe intellectual disability. Most affected individuals have limited or no speech, as well as behaviour problems. Most have structural abnormalities of the brain resulting in seizures. There may also be weak muscle tone and swallowing difficulties.
Physical characteristics include a small head that is also unusually short and wide in proportion to its size. There might also be vision or hearing problems, and abnormalities of the skeleton, heart, gastrointestinal system and other organs.
22q11.2 deletion syndrome (DiGeorge Syndrome) is caused by a missing section of chromosome 22. This deletion has the potential to affect most of the system in the body and may cause a wide range of health problems like heart defects, palate differences, immune system problems, growth delay, kidney problems, hearing loss or others health problems.
7q Williams syndrome is caused by a deleted region from chromosome 7q Williams syndrome is a developmental disorders that affects many parts of the body. The syndrome is characterized by mild to moderate intellectual disability or learning problems and heart and blood vessel (cardiovascular) problems.
The affected individuals are most likely to have distinctive features including a broad forehead, a short nose with a broad tip, full cheeks and a wide mouth with full lips. This disorder also tends to affect their dental health such as smaller teeth, widely spaced, crooked or missing.
(Koolen De Vries Syndrome)
17q microdeletion syndrome (Koolen De Vries Syndrome) is a disorder that is caused by a small missing genetic material from chromosome 17. The affected individuals are usually characterized by high and broad forehead, droopy eyelids, round nose and prominent ears. This disorder may causes hearing or other cardiac abnormalities, kidney problems and skeletal anomalies such as foot deformities.
17p- Smith-Magenis syndrome is a disorder that caused by a deletion from a region of chromosome 17. This disorder usually affects many parts of the body including mild to moderate intellectual disability, delayed speech and language skills, sleep disturbances and behavioral problems. Most of the affected individuals have a broad, square-shaped face with deep-set eyes, full cheeks and a prominent lower jaw.
(Prader Willi / Angelman Syndrome)
Most mothers carrying babies with a 15q11.2 microdeletion experienced no pregnancy problems, had a normal delivery and only discovered their baby was affected after the birth. There are two main types of syndrome associated with this microdeletion.
- Angelman syndrome results from a loss of gene activity (expression). Main characteristics of Angelman syndrome includes severe mental retardation, lack of speech, excessive happy demeanour.
- Prader Willi syndrome is caused by a loss of active genes in a region of chromosome 15. People can have either Prader-Willi syndrome or Angelman syndrome. Characteristics of Prader-Willi syndrome includes mild to moderate development delay, delayed to no puberty.
18 Deletion syndrome is chromosomal disorder that caused by a missing piece of chromosome 18.
The affected individuals with 18q Deletion syndrome usually have intellectual disability and delayed development, however some affected individuals have normal intelligence and development.
4p-Wolf-Hirschhorn syndrome is a chromosomal condition that caused by a missing section of chromosome 4. This chromosomal disorder causes delayed growth and development, intellectual disability and seizures. The affected individuals have distinctive facial features, including a broad, flat nasal bridge and a high forehead.
The above conditions indicated are found in the full panel of iGene test (iGene Plus) only.For more information or advice, please speak with your obstetrician or click here to enquire.
Aneuploidy: a condition in which a person has one or a few chromosomes above or below the normal chromosome number (46). It originates during meiosis (a cell division process that gives rise to the sperm and egg) when the chromosomes do not separate properly between the two cells. For example, a common form of aneuploidy is when an individual have 3 copies of chromosome 21, which is more commonly known as Down syndrome.
(Week of pregnancy)
- OSCAR: One Stop Clinic for Assessment of Risk for Fetal Anomalies that includes ultrasound measurements of Nuchal Translucency (NT) and biochemical testing,
- Nuchal Translucency Screening: An ultrasound scan that measures the thickness of the fetal nape (neck) to identify the risk of chromosomal abnormalities.
- Triple Test: Measures the levels of a protein produced by the fetus as well as two pregnancy-produced hormones in the maternal blood.
- False Positive Rate: The rate at which a positive result is incorrectly identified, when there is no chromosomal abnormality is present.
- PPV: Positive predictive value is one of the most important measures of a screening test. It measures the probability that a positive result is truly positive, or the proportion of patients with positive test results who are correctly identified.
If the screening results come back negative, it suggests a low risk for the tested trisomies. Otherwise, women who screen positive for a particular chromosomal abnormality are advised to consult their obstetrician / doctor for further action, which may include a diagnostic confirmatory test, such as Amniocentesis or Chorionic Villus Sampling (CVS).
Once pregnant, can I sign up for iGene™?
Am I eligible for iGene™?
Besides iGene™, what other screening tests are available to detect chromosomal abnormalities?
How do I sign up for iGene™?
Are iGene™ results conclusive for a chromosomal disorder?
- Jiang F, et al. BMC Medical Genomics, 2012 Dec;5:57. doi:10.1186/1755-8794-5-57
- Bianchi et al. 2014. The New England Journal of Medicine, 2014 Feb, 370:799-808.
- Nicolaides, K. 2011. Prenatal Diagnosis, (31), 7-15.
- Dan et al., Prenatal Diagnosis 2012; 32; 1-8.
- Zhang H, et al. 2015. Ultrasound Obstet. & Gynecol. 10.1002/uog.14792.