@genetic-counselor
Genetic Counselor
Forum Replies Created
-
Posts
-
Your genetic makeup doesn’t change, so a result for a specific gene doesn’t need to be repeated. However, a new or broader test may be recommended later if earlier testing didn’t provide an answer, or if newer testing technology becomes available.
Yes. Prenatal genetic testing can be done during pregnancy using a blood sample from the mother (screening) or, when needed, a sample from the amniotic fluid or placenta (diagnostic testing). Your doctor will recommend the safest option based on your situation.
No fasting or special preparation is usually needed. You can eat and drink normally before your sample is collected.
Living well with Marfan syndrome is mainly about staying one step ahead of potential complications through consistent follow-up, rather than trying to “prevent” the condition itself. Here is a detailed breakdown of what this looks like in practice:
1. Regular heart monitoring
*An echocardiogram is typically done once a year to measure the width of the aorta and check valve function. Your cardiologist may recommend more frequent scans (every 3–6 months) if the aorta is enlarging or already wider than a certain threshold. This is the single most important habit, because aortic widening usually has no symptoms – the only way to catch it early is to look for it on a scan, consistently, even when feeling completely well.
2. Medication to protect the aorta
*Doctors often prescribe beta-blockers (or, in some cases, angiotensin receptor blockers/ARBs, such as losartan) even before any symptoms appear. These medications work by reducing the force and pressure of each heartbeat, which in turn reduces the mechanical stress on the aortic wall over time.
*These medicines are usually meant to be taken long-term and consistently, not just when symptoms are felt – stopping them without medical advice could remove this protective effect and cause serious harm.3. Adjusting physical activity – not avoiding it altogether
*High-intensity, contact, or straining activities are best avoided, including competitive contact sports (like rugby or football), heavy weightlifting, and activities involving sudden bursts of exertion or a risk of chest impact.
*Low-to-moderate intensity activities such as walking, swimming at a comfortable pace, cycling on flat terrain, or doubles tennis are generally considered safer and are actively encouraged, as staying reasonably active is good for overall cardiovascular health. The exact activity plan should always be personalized with a cardiologist, since it depends on the current aortic size and whether any prior heart issues exist.4. Annual eye examinations
*A dilated eye exam by an ophthalmologist, ideally once a year, helps catch lens dislocation, high myopia progression, early cataracts, glaucoma, or retinal changes before they cause vision problems. Many of these issues are very manageable when caught early.
5. Orthopedic follow-up
*Especially important during childhood and the adolescent growth spurt, when scoliosis can progress quickly. Regular spine checks allow bracing or other interventions to be considered at the right time if needed.
6. Dental care
*Routine dental check-ups help manage the crowded teeth and high-arched palate that are common in Marfan syndrome, and catch issues early.
7. Antibiotic cover before certain procedures
*Some patients may be advised to take a short course of antibiotics before dental work or certain surgical procedures depending on whether there is valve involvement or not, to reduce the risk of an infection settling on the heart valve. This should always be based on your cardiologist’s specific advice, not assumed automatically.
8. Planning pregnancy carefully
*Pregnancy increases strain on the heart and blood vessels, so women with Marfan syndrome are strongly encouraged to have a thorough cardiovascular assessment before conceiving, and to be monitored closely by a team including a cardiologist and a maternal-fetal medicine specialist throughout pregnancy.
9. Genetic counseling for family planning
*Since each child of an affected parent has a 50% chance of inheriting the condition, genetic counseling can help families understand their options – including early testing of children, and reproductive options such as prenatal or preimplantation genetic testing, if desired.
10. Staying connected with a coordinated care team
*Because Marfan syndrome affects multiple organ systems, the best outcomes generally come from a team approach consisting of a geneticist, cardiologist, ophthalmologist, and orthopedic specialist working together, rather than each issue being managed in isolation.
Marfan syndrome affects different parts of the body differently. No two people have the exact same combination or severity of features – some people have mild changes, others have more pronounced ones. Here is what to look out for, system by system:
*Body build and skeleton: People with Marfan syndrome are often unusually tall and slender, with long arms, legs, fingers, and toes (this finger appearance is called arachnodactyly, meaning “spider fingers”). The arm span may be greater than the person’s height. Joints are often more flexible (“loose-jointed”) than average.
*Chest wall: The breastbone or the sternum, located in the center of the chest, may either sink inward (pectus excavatum) or push outward (pectus carinatum), giving the chest an unusual shape. This can sometimes affect breathing comfort or heart positioning.
*Spine: A sideways curve of the spine, called scoliosis, is common and tends to progress during the fast-growth years of childhood and adolescence.
*Feet: Flat feet are frequently seen.
*Face and mouth: A long, narrow face, a high-arched roof of the mouth (palate), and crowded teeth are common features.
*Eyes: This is an important area to monitor. The lens of the eye can shift out of its normal position (called lens dislocation or ectopia lentis), which is one of the most specific signs of Marfan syndrome. People are often also significantly nearsighted (myopic) from a young age, and are at higher risk of retinal detachment, cataracts, and glaucoma later in life.
*Heart and blood vessels: This is the most medically significant area. The walls of the aorta (the large blood vessel carrying blood from the heart to the rest of the body) can weaken and gradually widen over time causing a condition called aortic root dilation. The heart valves, especially the mitral valve, can also become “floppy” (mitral valve prolapse), sometimes causing an irregular heartbeat or a feeling of the heart skipping.
*Skin and lungs: Stretch marks (unrelated to weight changes) can appear on the skin. Some people are more prone to a collapsed lung (pneumothorax).Because these features can appear gradually and vary so much, some people are only diagnosed as adults, especially if their case is mild or if no one in the family was previously diagnosed.
Yes, it can be inherited, but it can also occur without any family history at all.
Marfan syndrome follows what’s called an autosomal dominant pattern of inheritance. In simple terms, this means a person only needs one altered copy of the FBN1 gene (out of the two copies everyone carries) to have the condition. If one parent has Marfan syndrome, each of their children has a 50% (1 in 2) chance of inheriting it, regardless of the child’s sex. This is often explained to patients using a simple coin-toss analogy where every pregnancy is an independent “toss,” so having one unaffected child doesn’t change the odds for the next.
However, about 1 in 4 cases (25%) occur in people with no family history at all. These are called de novo mutations or in simple words new mutation, where the genetic change happens for the first time in that individual, often during the formation of the egg or sperm, and was not present in either parent. In such cases, the parents’ risk of having another affected child is very low, though genetic counseling can help clarify this further.
Marfan syndrome is a genetic condition that affects the body’s connective tissue which is the material that acts like “glue and scaffolding,” holding together and supporting organs, blood vessels, bones, and skin.
The condition is caused by a change in a gene called FBN1. This gene carries the instructions for making a protein called fibrillin-1, which is a key building block of connective tissue. When this protein doesn’t work properly, connective tissue throughout the body becomes weaker and more stretchable than it should be. Because connective tissue is present almost everywhere in the body, Marfan syndrome can affect several systems at once – most importantly the heart and blood vessels, but also the eyes, bones, joints, skin, and lungs.
It’s important to understand that Marfan syndrome is not caused by anything the person or their parents did during pregnancy or childhood. It is simply how a particular gene was inherited or, in some cases, how it changed spontaneously.
The seriousness of Marfan syndrome comes almost entirely from its effect on the aorta, not from how a person looks or how tall they are.
The aorta is under constant pressure from every heartbeat. In Marfan syndrome, the weakened connective tissue in the aortic wall means it can gradually stretch and widen over months or years – often with no symptoms at all in the early stages. This is what makes regular monitoring so important: a person can feel completely well while the aorta is quietly enlarging.
If the aortic widening becomes severe and is not caught in time, it can lead to an aortic dissection (a tear in the inner layer of the aortic wall) or aortic rupture – both of which are medical emergencies and can be fatal within minutes to hours if not treated immediately. This is the single biggest reason doctors emphasize regular heart screening for anyone with Marfan syndrome, even if they feel fit and symptom-free.
The encouraging part: with early diagnosis, regular monitoring, medication, and timely surgery when needed, this risk can be managed very effectively, and most people with Marfan syndrome today live long, full lives.
Not necessarily, and the interpretation depends heavily on context:
*If a specific familial variant has already been identified in a relative and your test doesn’t show it, this is a “true negative” and your risk returns to that of the general population.
*If no familial variant has been identified and you test negative on a broad panel, this is less conclusive. It may mean the cancers in your family are due to a different cause, or that current testing technology hasn’t identified the responsible change yet, however negative testing does imply that the genetic cause is likely to be low.
*A result may also come back as a “variant of uncertain significance” (VUS) – a genetic change that hasn’t yet been classified as harmful or harmless as the current research on the variant are insufficient to classify them. This does not confirm or rule out Lynch syndrome and is usually reviewed again over time as more data becomes available.Testing adds the most value at two points: at the time of a cancer diagnosis, where it can inform treatment decisions and can be eligible for certain immunotherapy drugs that work particularly well against Lynch-related tumors, and before any cancer develops, in people with a known family history, where it allows preventive planning to begin early. A confirmed positive result typically leads to:
*Colonoscopies starting around age 20–25, repeated annually or every 1–2 years.
*Additional screening for endometrial, gastric, or urinary tract cancers depending on the gene involved.
*Discussion of risk-reducing surgery (such as hysterectomy and removal of ovaries) once childbearing is complete, for those with a uterus.
*Cascade testing- offering a targeted segregation of the change found in proband to first-degree relatives, since each one independently has a 50% chance of carrying the same variant.*Those diagnosed colorectal or endometrial cancer before age 50.
*Those who had more than one Lynch-related cancer (Cancers in colon, uterine, ovarian, stomach, urinary tract, or small bowel).
*Multiple family members across generations have had cancers related to Lynch Syndrome.
*A close relative was diagnosed with colorectal or endometrial cancer before age 50, even if you yourself have not had cancer.
*A first-degree relative (parent, sibling, or child) has already tested positive for Lynch syndrome.
*Tumour testing findings indicates genetic causes, findings showed microsatellite instability (MSI-H) or abnormal mismatch repair (MMR) protein results on immunohistochemistry — this is often done automatically on colorectal or endometrial tumors and can prompt a referral for genetic testing.
*You have a personal or family history of multiple colon polyps, particularly if diagnosed at a younger age.
*Your family history meets formal clinical criteria used by doctors to flag hereditary cancer risk.Individuals with Lynch syndrome have a much higher lifetime chance of developing certain cancers compared to the general population – and these cancers can occur at a younger age than usual. The good news is that Lynch syndrome is one of the few hereditary conditions where knowing your status early can genuinely change your outcome, through closer monitoring and timely preventive care.
Lynch syndrome is an inherited condition that runs in families. It’s caused by certain changes in one of a few specific genes that normally help repair small errors in our DNA. When one of these genes isn’t working properly, it becomes easier for cancer to develop over a person’s lifetime – particularly colorectal (colon) and endometrial (uterine) cancer.
If a genetic condition or a specific gene change is identified in your family, close relatives such as siblings, parents, or children may benefit from testing as well, since they may share the same risk. Your geneticist can guide you on who in the family should consider testing.
There are three possible outcomes for a genetic disorder. A positive result means a gene change linked to a condition was found. A negative result means no such change was found in the genes tested. Sometimes a result comes back as a “variant of uncertain significance,” meaning a gene change was found, but it is not yet clear whether it causes the condition. Your geneticist will explain what your specific result means and what, if anything, to do next.
