What is Meromelia?
Meromelia is essentially when a person is born missing part of one or more limbs. The lack of a limb(s) can be due to a variety of factors including changes in chromosomes, genetic problems, exposure to harmful things while in the womb, or complications from a type of prenatal test called chorionic villus sampling. The term “amelia” refers to the complete lack of at least one limb. Although meromelia can be seen as a variation of amelia, it’s just a form of the same issue, with the main difference being how severe it is.
What Causes Meromelia?
In a study of birth defects involving the limbs, almost 65% of cases had a known cause. Looking at 162 children born with limb deformities, about 8% were due to abnormal chromosomes. The most common of these was Trisomy 18 (Edward’s syndrome), but other conditions such as thrombocytopenia-absent radius (TAR) syndrome and Trisomy 13 were also observed.
About 8.6% of the cases were due to a known disorder, association, sequence, or related abnormality. The most common in this group were VACTERL association, which includes several physical abnormalities, and anencephaly, a condition where a baby is born without parts of the brain and skull. Other conditions like cloacal exstrophy, encephalocele, sirenomelia, prune belly syndrome, and urethral atresia were also noted.
Genetic or inherited conditions were the cause in around 16.1% of cases. The most common of these was cleft hand syndrome (also known as ectrodactyly), but others like anemia, which is a blood condition, and Holt-Oram syndrome, a heart and hand condition, were also noted.
Exposure to harmful substances during pregnancy accounted for around 3.7% of cases, with most involving mothers who had diabetes. There was one case due to exposure to a drug called misoprostol before birth. However, it’s important to note that another medication, thalidomide, is commonly associated with causing severe limb abnormalities, even though it was not seen in this particular study.
Vascular disruptions, or problems with the blood vessels, accounted for 28.4% of limb defects. They were most often due to a condition known as amniotic band syndrome. Other less common causes were Poland syndrome and a condition involving twins where one does not fully develop (acardiac twins).
For the remaining 35.1% of cases, the cause of the limb deformities could not be identified.
Risk Factors and Frequency for Meromelia
Meromelia is a condition that affects newborn babies, leading to congenital limb deficiencies. It’s pretty rare, happening in about 0.00001.4% of live births. Looking at one particular study, out of 206,224 babies born, 162 had limb deficiencies. Just over 60% of these babies lived past their first month. More boys had these limb deficiencies than girls, and there were also cases where the baby’s gender was not determined.
- Meromelia is a rare condition that occurs in about 0.00001.4% of live births.
- In a study of 206,224 born babies, 162 had limb deficiencies.
- Just over 60% of these babies survived their first month.
- There were more boys (53.7%) than girls (39.5%) with limb deficiencies.
- The gender for some cases was not determined.
Signs and Symptoms of Meromelia
If a child is born with a short or malformed limb, doctors should check if there’s a family history of such limb abnormalities. They should also explore if the mother was exposed to certain medications during pregnancy. Two such medications, misoprostol and thalidomide, are known to cause limb abnormalities.
Doctors should also conduct a thorough examination to check for related health conditions, such as VACTERL anomalies or Fanconi anemia. These conditions can be life-threatening if not treated. Often, the specific type of the limb abnormality can provide doctors with clues about potential associated conditions, like thrombocytopenia absent radius syndrome.
Testing for Meromelia
If you may have an inherited disorder or certain chromosomal conditions like Edwards syndrome or Patau syndrome, your doctor might recommend genetic testing. These conditions involve having one extra chromosome (trisomy) in each cell. Edwards syndrome is also known as trisomy 18, and Patau syndrome is also known as trisomy 13.
Alongside genetic testing, X-rays and a special kind of test called vascular mapping are also usually done for people with shortened limbs. This is to precisely identify the extent and nature of the limb deficiency. The findings from these tests then help doctors plan the best treatment approach and decide on suitable prosthetics if needed.
Treatment Options for Meromelia
If a child is born with a limb deficiency, the first thing doctors will do is check for any other health problems, especially related to important organs like the heart and intestines. If doctors suspect there might be issues with these organs, they will refer the child to specialists like pediatric cardiologists (heart doctors for children) and gastroenterologists (doctors who handle digestive system issues).
In terms of dealing with the limb deficiency itself, doctors may consider prosthetics – artificial body parts – to help with appearance and function. But, many people with limb deficiencies actually adapt very well without prosthetics, even if the limb deficiency is severe. To help families adjust to these situations, physical and occupational therapy can be beneficial. These types of therapy can help children learn to perform day-to-day activities according to their unique needs.
Having a child with a limb deficiency can also be emotionally difficult for parents. It could potentially cause trauma for some. Therefore, mental health services and counselling should be available to families and children in need. These services can provide emotional support and coping strategies for day-to-day challenges.
What else can Meromelia be?
Meromelia, a condition characterized by partial absence of a limb, can be associated with various causes. In over half of the recorded cases, there exists a known link or potential root cause. From these:
- Edward syndrome, also known as trisomy 18, frequently comes with congenital limb defects, making it the most common chromosomal abnormality associated with this condition.
- A certain deletion on Chromosome 1 can cause a condition called thrombocytopenia absent-radius syndrome.
- Inherited disorders like ectrodactyly and Fanconi anemia can also lead to meromelia in children.
- Non-inherited conditions such as VACTERL association are often seen together with this limb truncation deficit.
What to expect with Meromelia
According to a study conducted by Gold and his team, out of 162 babies born with congenital limb deformities, 101 babies (or 62.3%) were not only born alive but also survived the first month of life. On the other hand, 10 babies (or 6.2%) were born alive but unfortunately, didn’t survive past the first month. 17 babies (or 10.5%) were stillborn, and 34 babies (or 21%) were electively terminated.
On a more positive note, those who survive with these deformities generally can function very well. Despite their condition, with the right treatment and the use of prosthetics, they can take care of themselves quite effectively. This largely depends on the severity of their deformity.
Possible Complications When Diagnosed with Meromelia
The most dangerous issues linked to limb shortening defects are often due to related abnormalities. For instance, meromelia, which often presents with the VACTERL syndrome, can lead to complications due to associated heart, intestine, kidney and other inborn defects. Additionally, individuals with Fanconi anemia have an increased likelihood of aplastic anemia, which is a condition where your body stops producing enough new blood cells. There’s also TAR syndrome, which can lead to low platelet count in the blood or thrombocytopenia.
Common Issues:
- Heart defects
- Intestine defects
- Kidney defects
- Other inborn defects
- Aplastic anemia
- Low platelet count in blood
Preventing Meromelia
Strengthening drug safety regulations could help reduce the chances of developing limb deformities, which can be potentially caused by certain drugs like misoprostol and thalidomide. It’s also worth mentioning that uncontrolled diabetes during pregnancy can potentially cause birth defects. Therefore, proper prenatal care, including managing diabetes, can also help reduce the risks of limb deformities in newborns.
Even with these factors in mind, it’s important to stress that the condition of having parts of the limb missing, known as meromelia, is very rare. Many times, such cases can’t be prevented. So if a child is found to have a limb deformity, it’s crucial to thoroughly evaluate their condition to ensure their best care and chances of survival.
For the best care, parents should have their child checked by an appropriate primary doctor, a geneticist, a heart specialist (cardiologist), kidney specialist (nephrologist), and/or digestive system specialist (gastroenterologist) depending on the other conditions the child might have. Additionally, physical and occupational therapy can be of great help in improving the child’s functional abilities.
