Marfan Syndrome is one of the disorders known to affect the growth and development of children as well as young adults. It is a genetic disorder that occurs due to the mutations in the genes that play a role in determining the growth and the adult height of individuals.
Marfan Syndrome may affect the growth in several ways due to which the adult height of the person could be affected.
Here is a detailed analysis of how tall a person with Marfan Syndrome can be and how this condition affects growth.
What is Marfan syndrome?
Marfan syndrome refers to an inherited disease that primarily affects the connective tissue causing abnormalities related to the normal body growth and development of vital organs and structures.
The connective tissue forms a critical part of some of the most important organs of the body that provide strength and support. These organs include the bones, joints, blood vessels, the walls of the intestine, skin, eyes, and the nervous system.
Disorders that affect the formation of the connective tissue, including the Marfan syndrome, can lead to widespread effects as almost every organ of the body comprises connective tissues as its supportive network.
The obvious physical characteristics of this disorder include being taller than usual, with a lanky appearance, having loose joints with larger and flat feet, and having disproportionately longer fingers.
These changes are basically linked to the formation of excessive connective tissues, due to which the organs and other structures like bones and muscles become unusually longer.
At the same time, the excessive formation of connective tissues is not coupled with a proportionate improvement in the strength.
As a result, even though the bones and muscles are comparatively longer in patients with Marfan syndrome, they are not necessarily strong enough to support the body weight or maintain balance.
These characteristics mark the appearance of patients with Marfan syndrome.
The abnormal changes linked to the growth and formation of the connected tissues are responsible for the increase in height and the lengths of their forearm, hands, legs, and fingers.
Marfan syndrome can affect men as well as women. It can affect people of all races and ages. It is a very rare disorder affecting about 1 in 5000 people. 
Symptoms and consequences of Marfan syndrome
It is important to be aware of the symptoms of Marfan syndrome to be able to recognize the abnormal changes occurring due to the same. Here are some signs that point to the diagnosis of Marfan syndrome.
The symptoms of Marfan syndrome are often evident in children during infancy and early childhood.
In rare cases, the symptoms may appear during early adulthood resulting in a delayed diagnosis.
Being aware of the symptoms can help to assess the impact of this condition on the growth of the child and determine his or her adult height. Appropriate measures can be adopted based on the severity of Marfan syndrome in children depending on their symptoms to minimize the adverse effects linked to the formation of connective tissue in them.
Read on to learn the common early signs of Marfan syndrome that indicate the impact of this condition on the child’s development and expected adult height.
The Marfan syndrome exhibits itself differently among different patients. The common evident symptoms occur in the bones and joints.
As discussed earlier, patients may have an unusually tall height with very long limbs and large or flat feet.
They may also have long and thin fingers and loose joints as a result of which they may experience difficulties in walking and maintaining balance.
A curved spine is another characteristic feature of Marfan syndrome. The abnormal curvature of the spine is believed to be linked to the excessive growth of the connective tissues in the vertebral column as well as the lack of strength of these tissues to support the back.
In some cases, the curvature of the spine could be the result of the tendency developed by the patient to bend or hunch as is often observed in very tall people. The bending of the spine may give a perception of a slightly lower height in such cases, though the actual height of the patient is more than the average height for his or her age.
In most cases, patients with Marfan syndrome have a prominent chest bone called the sternum that seems to be caved inward or stuck out. They may also have crowded teeth, an unusual appearance that could be attributed to the higher arch of the roof of the mouth due to the increased connective tissues.
It is these changes in the skeletal system of the children with Marfan syndrome that are primarily responsible for their abnormally taller height.
Other than these, patients may also exhibit other signs that may or may not be directly related to their taller stature but are important from the point of view of timely diagnosis and treatment.
Let us have a look at some other common signs of Marfan syndrome caused due to the increased connective tissue formation in other organs and structures.
Blood vessels and heart
The more invisible signs of Marfan syndrome occur in the heart and blood vessels of the patients.
The aorta, which is a large blood vessel responsible for carrying blood away from the heart, might become enlarged. In most cases, an enlarged aorta may not cause any symptoms, though it carries a risk of life-threatening complications such as rupture.
The rupture of the aorta may occur due to the longer but weaker connective tissues in the aorta that is unable to stretch too much to accommodate the rush of blood entering it from the left ventricle with a great force.
The weakness of the walls of the aorta prevents this blood vessel from withstanding the high pressure due to which it becomes distended like a balloon. Over a period of time, the walls of the aorta may give up resulting in a rupture.
The rupture of the aorta is considered an emergency that needs to be attended to immediately. Hence, patients with Marfan syndrome are advised to assess their cardiovascular health on a regular basis with the help of advanced diagnostic testing that provides a measurement of the blood vessel diameters and the flow of blood through them.
Patients with Marfan syndrome are likely to develop problems related to their eyesight such as near-sightedness. About 6 in 10 patients with this condition develop “partial lens dislocation” in the eyes. 
Being aware of these subtle signs of Marfan syndrome can help in the early diagnosis of this condition and enable patients to receive appropriate treatment.
What are the causes of Marfan syndrome?
Marfan syndrome is an inherited disorder that is transmitted through the autosomal dominant mutations of the gene encoding glycoprotein called the FBN1 (fibrillin-1) that plays a role in promoting the anchoring of the cells to extracellular matrix. 
It is the main component of supportive tissue called the microfibrils.
These microfibrils tend to affect the elasticity and strength of the connective tissue and control the release of growth factors, which cause the growth of tissues and organs in the body. 
Any defect in this particular gene could mean the quality and the quantity of FBN1 in the body would be decreased, due to which the amount available to produce microfibrils would be less. This is the reason why patients with Marfan syndrome develop complications related to the abnormal changes in the connective tissues and the growth of the bones, ligaments, and muscles. 
Disease-specific growth charts in patients with Marfan syndrome
Clinical data collected retrospectively from the review of medical records of patients diagnosed with Marfan Syndrome have provided insights into how this disease can affect the growth of a person and how taller he or she can be.
Assessment of nearly 350 patients diagnosed with Marfan Syndrome according to the revised Ghent criteria between 1995 and 2013 have revealed a considerable increase in height in them compared to the children of the same age group.  
Among these, 9 patients had received a high dose estrogen therapy for inducing growth reduction due to which they were excluded from the assessment.
Statistical analysis of these participants based on the centile curves was constructed using the Pro version 2.54 software program of the LMS Chart Maker designed by the Institute of Child Health, London, UK.
The chart was used to fit or correlate the smooth centile curves in these patients to the reference data of the average weight and height of patients with Marfan syndrome using the LMS method.
The growth data in these participants available from 187 boys and 152 girls through a retrospective review of their medical records and the statistical analysis of 651 weight measurements and 586 height measurements in males and 665 weight measurements and 596 height measurements in females has provided the basis for measuring the increase of height in children with Marfan syndrome.
The analysis has shown that a majority of patients had a longitudinal improvement in height as described below.
The change in the height of patients with Marfan Syndrome based on the height growth curve
Research studies were conducted to assess the increase in the height of patients with Marfan syndrome based on the height growth curve.
It was surprising to note that up to the initial 10 to 12 months of age, the height growth curve of the participants tended to be quite similar to that of infants without Marfan Syndrome or any abnormality linked to their growth and development.
These findings were observed in both male and female infants.
During the 2nd years of life, the mean height of boys showed a sudden spurt in growth due to which they were taller than the normal children in the same age group.
The increase in height in the second year was 90.5 ± 10.6 cm in boys with Marfan syndrome as against only 82.1 ± 3.3 cm in normal boys.
The increase in height in the second year was 90.4 ± 4.8 cm in girls with Marfan syndrome as against only 80.8 ± 3.2 cm in normal girls.
This showed that the effect of Marfan syndrome on the growth and height of infants starts becoming evident usually in the second year of life on both boys and girls.
The mean height of boys and girls with Marfan syndrome continued to be significantly higher than that of the normal children of the same age even in their early childhood.
The change in the height after this age was striking in boys. It was found that the 3rd percentile of their statural growth curve was coinciding with the 75th percentile of the normal statural growth at 4 years.
Later, it crossed the 50th percentile of the normal statural growth curve by the 5th year of age and remained at a higher level at around the 25th to 75th percentile by the age of 8 years.
Thereafter, the statural growth curve was similar to the 75th percentile of the normal curve by 13 years of age.
The mean adult height in boys with Marfan syndrome was 189.8 ± 4.4 cm, which was above the 97th percentile for most adult males in the group of participants.
Similar changes were observed in the height of girls with Marfan syndrome.
The findings revealed that the 3rd percentile of the standard curve of girls with this condition coincided with the 75th percentile of the curve by 13 years of age. It remained at around the 50th to 75th percentile by 15 years of age.
The mean adult height in girls was 177.1 ± 6.0 cm, which was above the 97th percentile for the normal girls in the group of participants.
The result of this study has provided evidence showing that the average height of men and women with Marfan syndrome is considerably higher than that of normal people.
Also, the increase in the height begins to be evident at a very young age. The characteristic taller stature of kids with Marfan syndrome persists until they reach their early adulthood.
Linear growth pattern in patients with Marfan Syndrome
Several differences have been observed in the average height of kids of different age groups with Marfan syndrome across different countries.
Disease-specific growth charts are commonly used to assess the change in the heights of patients who suffer from diseases that can affect their growth and development including Marfan syndrome and Down syndrome.
Studies have found that the average adult height of patients with Marfan syndrome in Korea is around 191.4 ± 5.2 cm in men and 176.2 ± 5.3 cm in women.
The disease-specific growth charts followed in the US have shown the average adult height to be 191.3 ± 9.0 cm in men and 175.4 ± 8.2 cm in women with this condition.
It should be noted that there is not much difference in the average heights of men and women with Marfan syndrome in Korea and the US. The mean adult heights in these countries have a considerable difference. The average heights of men in Korea and the US are 173.3 cm and 176.7 cm, respectively. Also, the average heights of women in Korea and the US are 160.7 cm and. 163.1 cm, respectively.
This suggests that though the average height of patients with Marfan syndrome is similar in patients in Korea and the US, the increase in height is comparatively higher in those from the US. 
How to avoid the impact of increased height on stability and balance?
Patients with Marfan syndrome are likely to develop serious musculoskeletal disorders early in life and even during adulthood.
Physical activity is an area of concern for these patients. Children and adults with Marfan syndrome are prone to injuries due to a number of factors.
The taller height raises the center of gravity of their body to a higher level than it should normally be. The higher level of the center of gravity may reduce their ability to balance themselves making them prone to falls and injures.
Moreover, the thin and slender frame of their body further adds to the issue of maintaining stability. The reduced total body mass compared to the height reduces the efficiency of reflex actions like spreading the hands quickly in order to maintain balance when faced with an event like a missed step.
These effects of Marfan syndrome necessitate patients to be more careful while walking, running, or performing physical activities.
They should avoid participating in certain contact or competitive sports such as football, baseball, gymnastics, soccer, basketball, weightlifting, track, and volleyball. These activities can not only increase their risk of falls but also create more strain on the lungs and heart with the potential risk of trauma or blow to the chest or rib cage.
However, this doesn’t mean patients with Marfan Syndrome need to keep away from sports and physical activities completely. They can try adaptive physical education plans to participate in these activities at their own level.
Low-impact activities and non-competitive sports such as swimming, dancing, bike riding, and walking could be perfect for them. These activities can allow them to get the exercises needed to stay fit and healthy.
They can also consult a physician to determine the physical activities that could be more appropriate for them. 
The height of young boys and girls, as well as adults with Marfan syndrome, tends to be considerably more than that of other children and adults of the same age. It is possible to avoid the excessive increase in height by undergoing treatments that slow down growth.
Other than these, patients should also modify their lifestyle such that the increased height does not create difficulties for them while performing physical activities.
Being aware of how to reduce the risk of falls and injuries and adopting strategies to avoid these complications could allow patients with Marfan Syndrome to live a safe and healthy life.