congenital anomaly congenital anomaly

What Is Congenital Anomaly and Its 3 Types

Want to know what is congenital anomaly1? ‘Anomaly’ refers to something different or deviating from what is considered normal. It is a medical condition that refers to a huge spectrum of abnormalities.2

Congenital anomalies often occur before birth and are naturally inherited in nature. These disorders can be present before or at the time of delivery in an individual. Hence the word ‘congenital.’

The congenital anomaly could be functional or structural in nature. They are also referred to as birth defects, congenital malfunctions, or even congenital disorders. Some congenital anomalies3 can be treated, while a few are permanent.

Individuals living in low-income countries are highly affected by congenital anomalies. They have a long-lasting impact and are more severe in nature as the country lacks proper treatment centers.

Improper healthcare facilities leave the affected untreated or undertreated, increasing the health risks in the country. It is also important to note that birth defects occur to three lakh deaths yearly.

There are external and internal congenital anomalies, which are chromosomal too.

1. Chromosomal Abnormality

Chromosomes are thread-like structures that hold the genes of an individual. They direct an individual’s bodily characteristics, such as eye colour, height, and many other features.

These chromosomes are found in the nucleus of the cell. Whenever there is a defect in the number of chromosomes or the structure of chromosomes, we refer to it as a chromosomal abnormality4.

1.1. Down Syndrome

Down syndrome is a congenital condition caused due to the presence of an additional Chromosome Number 21 responsible for the development and other physical features. This syndrome is called Trisomy 21, as the person has three chromosomes, 21 instead of two.

This condition causes delays in the mental and physical development of the child. This congenital anomaly cannot be cured; however, the symptoms can be reduced with treatment.

This condition cannot be prevented if the parent has already potential to give birth to a child with Down syndrome. In these conditions, one must take up genetic counselling on whether or not one wants to have a baby. This is tally a subjective decision, which could be made easier with professional help.

Individuals with Down’s syndrome have other medical complications with this disorder. They include heart defects, weakened immunity or other immune disorders, spinal problems, and many more. Individuals affected with the same also have a higher risk of disorders such as dementia5 and leukemia. 

 Symptoms of Down’s Syndrome

  1. Small Head
  2. Small Ears
  3. Short Neck
  4. Short Height
  5. Smaller Fingers and Hands
  6. Flattened Face
  7. Protruding Tongue
  8. Loose Joints
  9. Learning disabilities
  10. Delay in speech development
  11. Intellectual disabilities
  12. Poor memory

1.2. Edward’s Syndrome

Another chromosomal abnormality is caused due to the presence of an extra Chromosome 18. This probability of a child having Edward’s syndrome or any other congenital anomaly that is chromosomal in nature increases if the mother’s maternal age is higher.

This congenital anomaly is more prevalent in females than males and affects the body’s physical development. This condition currently has no possible treatment.

Symptoms of Edward’s Syndrome

  1. Low birth weight
  2. Small head
  3. Abnormal fingers
  4. Short stature
  5. Underdeveloped jaw
  6. Poor muscle tone
  7. Club feet
  8. Lung abnormalities
  9. Heart abnormalities

Edwards Syndrome, Causes, Signs and Symptoms, Diagnosis and Treatment.

There are other chromosomal congenital anomalies that include Tay-Sachs disease, Cystic fibrosis, and many more. These conditions can be autosomal dominant recessive6, or x-linked conditions.

X-linked conditions are those chromosomal abnormalities that are caused due to some defect on the X chromosome. Some of them include colour blindness, hemophilia, sickle cell anemia, and many more.

Some chromosomal abnormalities become definite if they are supported by environmental conditions during pregnancy. Smoking, drinking, and many other unhealthy practices affect the child’s development, increasing the probability of a chromosomal abnormality7 becoming prominent.

2. External Congenital Anomaly

2.1. Neural Tube Defects

They are complex disorders that cause brain, spine, or spinal cord abnormalities. It is often developed in the first month of pregnancy. Hence, the mother must consume sufficient folic acid to prevent the disorder.

2.1.1. Anencephaly

Anencephaly is a condition where the child is born with an underdeveloped brain. The child might also have an incomplete skull or scalp. Unfortunately, babies born with birth defects do not survive after birth.

It is caused when there is a mutation in the gene and when the mother remains in environmental factors that aid the mutation’s execution.

Hence, to prevent it, the mother is advised to stay away from unhealthy diet habits, drinking, smoking, and consumption of other harmful drugs that potentially affect the baby.

2.1.2. Iniencephaly

Another extremely rare congenital anomaly is caused due to neural tube defects in this condition, where the baby has a defect in the occipital bone.

This condition is caused by inappropriate closure of the individual’s neural tube. This also occurs in the womb of the mother.

2.1.3. Spina Bifida

This congenital anomaly is again caused due to a defect in the neural tube. This is a condition where the individual’s spinal cord or spine is not developed properly. Individuals with the disorder may have a protruding spine that could cause many complications. This defect can be mild, moderate, or severe, depending on the location of the defect.

Surgery can be tried to treat the defect, but there is no guarantee of how much can be resolved in surgery. This congenital anomaly is chronic, and the treatment only focuses on reducing the symptoms.

2.1.4. Craniorachischisis

This is the most severe of every other neural tube defect in the list of congenital anomalies. The disorder is characterized by the absence of a cranial vault, remains of brain tissue, or the absence of the brain.

Since the probability of survival is low or almost nill for individuals with the above-mentioned congenital anomalies, it is advised that regular ultrasound tests be taken to detect the presence of congenital anomalies at the earliest possible.

2.2. Gastroschisis

congenital anomaly
PublicDomainPictures. Pixabay. Copyright 2022.

This congenital anomaly occurs when the fetus is developing in the mother’s womb. The cause of this defect is very unclear even today. However, what is known about the symptom is that it causes difficulty in absorption.

It causes difficulty in the gut movement, the intestine is unhealthy and continues to stick to the wall of the abdomen, and there could also be some lumps in the abdomen.

It is essential to conduct Prenatal ultrasonography8, which will reveal the presence or absence of the congenital anomaly. The disorder can also be identified if the mother has excess amniotic fluid.

To confirm the presence of the disorder, it is crucial to give undivided attention to the baby’s growth. Regular tests and monitoring of the progress are necessary.

One must be prepared for complications so that the baby is immediately treated for them. The mother must also focus on consuming nutritious food to help the baby develop.

Whether there is a defect or not, the mother needs to consume a highly nutritious diet to help the child develop healthily. The mother must also be cautious of her lifestyle choices and keep herself healthy and far from vulnerable environments as much as possible.

2.3. Microcephaly

Microcephaly is a congenital anomaly where babies are born with smaller heads. This happens due to underdevelopment of the brain or due to some sort of brain abnormality. A child may be born with this congenital anomaly if the fetus is undernourished.

The child may be more vulnerable to this congenital anomaly if the mother has exposed herself to an unhealthy environment. This includes consuming alcohol, tobacco, or smoking any other kind of drug.

congenital anomaly
Picudio. Pixabay. Copyright 2022.

In addition, it might also be caused due to certain infections a mother is exposed to during pregnancy. These infections include toxoplasmosis, an infection caused by the Toxoplasma gondii parasite that usually resides in uncooked meat.

Hence, food must be properly cooked, especially meat, as they are hosts to several parasites, as human beings are.

Another potential infection that causes microcephaly is rubella, an infectious virus that causes both development delay and, in worst-case scenarios, even miscarriage. This infection can easily be avoided through a vaccine.

Nevertheless, the mother and her immediate family must be cautious of the surroundings the mother resides.

Microcephaly, like most other congenital anomalies, has no treatment. The symptoms, however, could be managed or reduced through varied treatments.

Symptoms of Microcephaly

  1. Short stature
  2. Poor hearing or loss of hearing
  3. Hyperactivity
  4. Poor vision
  5. Poor learning ability
  6. Delayed intellectual growth
  7. Restless or easily irritable

This congenital anomaly is often treated by therapy, such as occupational therapy. An occupational therapist uses varied everyday activities to treat behavioural and other mental symptoms. On the other hand, medications are also used to manage other underlying issues that come with microcephaly.

2.4. Club Foot

Club foot, also known as talipes, is a congenital anomaly where the baby is born with twisted feet or feet that are not in their normal position. This birth defect is not severe at all because, other than the foot, every other part of the baby is potentially healthy.

No one knows what causes club foot, but the good news is that it can be treated. The foot in this congenital anomaly could be inwards or upside down. Though it may seem like a very uncomfortable position, the baby specifically doesn’t undergo any pain due to club foot.

However, there will always be some sort of motor difficulties that the child will face. The child may also have shortened legs in this congenital anomaly.

In most cases, successful treatment is rendered. It includes the use of braces or other medical surgeries. Just stretching and casting do the wonders of healing in most cases.

There are two types of stretching used for this congenital anomaly; they include the Ponseti method and the French method.

While the Ponseti method treats clubfoot deformity by casting and stretching, the French method does the same by stretching and taping.

Surgery is also an option; usually, Achilles tenotomy is carried out. It is a way of correcting the club foot by making a small incision that allows the ankle to move upwards.

This is a minor surgery, and minimal pain may last for 1 to 2 days, but later, the person would feel normal again.

3. Internal Congenital Anomaly

3.1. Congenital Anomalies of the Heart

There are multiple anomalies depending on the location and type of defect at the heart. We shall discuss a few of them in detail to understand them better.

congenital anomaly
geralt. Pixabay. Copyright 2022.

3.1.1. Pulmonary Valve Atresia

This is a congenital structural anomaly, where the pulmonary valve is unusually closed or blocked, stopping blood flow through the right ventricular tract. This condition may or may not arise due to hereditary reasons.

But usually, it is a genetic defect or a chromosomal abnormality. The risk of this condition is higher if the family has a history of abnormality or other heart-related defects.

Most babies can survive if the valve is opened immediately through treatment; hence the hospital staff must be ready and prepared efficiently to save the life of the baby.

3.1.2. Common Arterial Trunk

Common arterial trunk, also known as common truncus, is another structural congenital anomaly of the heart. In this condition, the child will have one common aerial pathway instead of two (one pulmonary artery and one aorta).

This condition can be life-threatening; hence immediate treatment must be administered to the child.

It is always advised that surgery is carried out before the completion of the first month of the child to ensure the child can function normally.

3.1.3. Tetralogy of Fallot

A very complex, but it is a condition where a child is simultaneously born with four (hence the name tetra) heart defects. The child in this condition is affected by ventricular septal defect, misplaced aorta, right ventricular hypertrophy, and pulmonary stenosis. This results in extremely poor oxygen flow to the heart and the rest of the body.

Due to lack of oxygen, the child may have a tint of blue skin and shortness of breath. This congenital anomaly is chronic in nature and needs to be treated with great care and urgency.

This can be managed with surgery and medications, but one must be prepared as this could last lifelong.

3.2. Hypoplasia

A condition where cells are deficient in the tissue or organ. There are multiple types of hypoplasia: enamel hypoplasia, cardiac hypoplasia, testicular hypoplasia, optic nerve hypoplasia, and many more. The symptoms differ from one type to the other.

In a nutshell, optic nerve hypoplasia would have symptoms of poor vision and other visual-related defects, enamel hypoplasia would have teeth sensitivity issues, and cardiac hypoplasia would have issues related to heart tissues or the heart in itself.

The cause of this congenital anomaly is unknown, yet a lot of them do believe that it is hereditary in nature and is highly impacted by environmental factors.

For example, enamel hypoplasia is known to have been caused due to the deficiency of vitamin D during pregnancy. There is no cure for this birth defect in most cases, but it can be managed or controlled by regular medication and treatment.

3.3. Anorectal Atresia

This congenital anomaly is caused when a normal anal opening is absent at birth. This is usually healed with minor surgeries that are often carried out in the first few days of birth.

Congenital Anomalies | Patterns | Medical Genetics | USMLE | V-Learning

Frequently Asked Questions –

1. How are congenital anomalies diagnosed?

Ultrasound is the primary method in the prenatal detection of congenital anomalies.

2. Do congenital anomalies require treatment?

There is no need for treatment for some mild congenital abnormalities. On the other hand, serious structural defects frequently require surgery soon after delivery.

Conclusion

Some of these conditions are diagnosed during pregnancy through ultrasound. This is very helpful, as it keeps both the parents and the doctor informed and prepared for the situation to come.

It is often advised to take multiple scans or other diagnostic tests to look for potential defects. An early diagnosis will only help treat the birth defect better.

Most of these health problems are related to family history; hence they are hereditary in nature. Whether they are chromosomal abnormalities or chromosomal disorders, premature birth, metabolic disorders, cardiac defects, single gene defects, or in general, whether they are structural anomalies or functional anomalies, one must know that immediate treatment is significant.

It could be major congenital anomalies or minor congenital anomalies, but treatment is essential to treat birth defects. If not treated appropriately, there would be an increased risk of other health complications.

Certain birth defects are curable if the surgery or medication is given during or immediately after birth. Hence, regular tests must be taken to be up-to-date and carry out an effective treatment plan.

Most birth defects arise in middle-income countries or low-income countries, showing that there is a high need to establish proper healthcare systems across the world. Medical treatment must be easily accessible to people, and at the same time, it must also be affordable.

An individual with a congenital anomaly can still have an opportunity to live and function normally if appropriate treatment facilities are given. We must aim towards setting global health standards so that at least defects are currently curable cured and treated.

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  5. Leys, Didier, et al. “Poststroke dementia.” The Lancet Neurology 4.11 (2005): 752-759. ↩︎
  6. Vikkula, Miikka, et al. “Autosomal dominant and recessive osteochondrodysplasias associated with the COL11A2 locus.” Cell 80.3 (1995): 431-437. ↩︎
  7. Pylyp, L. Y., et al. “Chromosomal abnormalities in patients with infertility.” Cytology and Genetics 49.3 (2015): 173-177. ↩︎
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Last Updated on by Sathi Chakraborty, MSc Biology

Author

R Shishma Jeevitha

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