What is the Difference Between Anencephaly and Microcephaly

The key difference between anencephaly and microcephaly is that anencephaly is a birth defect where a baby is born without parts of the brain or skull, while microcephaly is a medical condition where a baby is born with a smaller head, or the head stops growing after birth.

Anencephaly and microcephaly are two conditions that affect the brain of babies. These conditions are also known as cephalic disorders. Both these conditions are related to problems with the development of the nervous system. These conditions are serious as they do not have exact treatments or cure.

CONTENTS

1. Overview and Key Difference
2. What is Anencephaly  
3. What is Microcephaly
4. Similarities – Anencephaly and Microcephaly
5. Anencephaly vs Microcephaly in Tabular Form
6. Summary – Anencephaly vs Microcephaly

What is Anencephaly?

Anencephaly is a birth defect where a baby is born without parts of the brain or skull. This is a neural tube defect (NTD). It is a birth defect in which the brain and bones of the skull of the baby don’t form completely when the baby is in the womb. The most affected part of the brain in this condition is the cerebral cortex, which is the part of the brain that is mainly responsible for thinking, movement, and senses such as touch, vision, and hearing. This is an incurable disorder that affects about three pregnancies per 10,000 in the U.S., according to Centres for Disease Control. The exact cause is not known. But it is believed genes or chromosomes, family history, and mother’s exposure to certain environmental toxins, medications, and food or beverages may play a role. The signs and symptoms of this condition may include missing parts of the skull (bone in the back of the brain), poorly formed bones on the sides or front of the skull, not properly formed brain, a folding of the ears, a cleft palate, poor reflexes, and heart defects.

Prenatal tests for anencephaly include blood tests, amniocentesis, ultrasound, and fetal MRI scan. Furthermore, there is no treatment or cure for this disorder. An infant born with this condition should be kept warm and comfortable. If any part of the scalp is missing, that part should be covered in order to prevent exposure to the outside.

What is Microcephaly?

Microcephaly is a medical condition where a baby is born with a smaller head than usual. This may be present at birth or may develop in the first few years. This medical condition is reported to occur in 1 pregnancy per 800 to 5000 in the U.S. The signs and symptoms of this condition may include a small head, receding forehead, loose and wrinkled scalp, being underweight and dwarfed, severely impaired intellectual development, neurological defects, seizures, delayed motor functions and speech, hyperactivity, intellectual disability, convulsions, clumsiness, or spastic quadriplegia. Most of the time, genetic mutations cause microcephaly. Genes causing microcephaly include MCPH1, WDR62 , CDK5RAP2 , KNL1 , ASPM, CENPJ, STIL, CEP135, CEP152,ZNF335, PHC1 and CDK6.

Microcephaly can be diagnosed through physical examination, ultrasound, and genetic testing. Furthermore, there is no cure for this disorder. The treatments include supportive care and treatment with amino acids to improve symptoms such as seizures and motor function delays.

What are the Similarities Between Anencephaly and Microcephaly?

• Anencephaly and microcephaly are cephalic disorders.
• These are two conditions that affect the brain of babies.
• Both these conditions are related to problems with the development of the nervous system.
• They are rare conditions.
• Both conditions can be diagnosed through imaging tests.
• There is no cure for both conditions.
• Both these conditions are serious as they do not have exact treatments or cure.

What is the Difference Between Anencephaly and Microcephaly?

Anencephaly is a birth defect where a baby is born without parts of the brain or skull, while microcephaly is a medical condition where a baby is born with a smaller head or the head stops growing after birth. Thus, this is the key difference between anencephaly and microcephaly. Furthermore, anencephaly affects about three pregnancies per 10,000, while microcephaly affects 1 pregnancy per 800 to 5,000 in the U.S.

The below infographic presents the differences between anencephaly and microcephaly in tabular form for side-by-side comparison.

Summary – Anencephaly vs Microcephaly

Anencephaly and microcephaly are cephalic disorders that commonly affect the brain of babies. Both these conditions can be due to genetic problems. Anencephaly is a birth defect where a baby is born without parts of the brain or skull. Microcephaly is a medical condition where a baby is born with a smaller head, or the head stops growing after birth. So, this summarises the difference between anencephaly and microcephaly.

Reference:

1. “Anencephaly: Neural Tube Defect, Birth Defect, Causes, Prevention.” Cleveland Clinic.
2. “Facts about Microcephaly.” Centers for Disease Control and Prevention, Centers for Disease Control and Prevention, 23 Oct. 2020.

Image Courtesy:

1. “Anencephaly-web” By Centers for Disease Control and Prevention, National Center on Birth Defects and Developmental Disabilities (Public Domain) via Commons Wikimedia
2. “Microcephaly-comparison-500px” By Centers for Disease Control and Prevention – (Public Domain) via Commons Wikimedia