What Is Iniencephaly?

Skull and brain deformities and abnormalities are typically congenital and in many cases genetic, except in cases of trauma. Diseases, disorders and abnormal development of skulls, brains and the spine range in severity from easily treatable to fatal. Genetic testing and screenings during pregnancy can help with early detection in cases of congenital abnormalities.


Iniencephaly is a rare birth defect caused by improper closure of the neural tube (the part of a human embryo that becomes the brain and spinal cord) during fetal development. The defect results in extreme retroflexion (backward bending) of the head combined with severe distortion of the spine.

Types of Iniencephaly

Iniencephaly is a rare neural tube defect. There are two types of iniencephaly: iniencephaly clausus with spinal defect and no cephalocele, and iniencephaly apertus with spinal defect and cephalocele. A cephalocele is defined as a herniation of cranial contents through a defect in the skull.

Causes of Iniencephaly

For reasons that are still unknown, the disorder is more common among females. No single gene has been identified as the cause for iniencephaly, or any of the neural tube defects. Scientists think these defects have complex causes, mostly likely a mix of genetic and environmental factors.

Risk Factors for Iniencephaly

Iniencephaly is more common with maternal exposure to extreme heat (such as saunas or hot tubs), smoking and alcohol. Additionally, the occurrence increases when the mother has a folic acid deficiency during pregnancy. Additionally, mothers who take anti-seizure medication or prescriptions for migraine headache and bipolar disorder are at higher risk of having a baby diagnosed with iniencephaly.

Screening for & Preventing Iniencephaly

Little is known about the rare disease of iniencephaly. For reasons that are still unknown, the disorder is more common among females. No single gene has been identified as the cause for iniencephaly, or any of the neural tube defects. Scientists think these defects have complex causes, mostly likely a mix of genetic and environmental factors.

Signs & Symptoms of Iniencephaly

The presence of chromosomal conditions, such as trisomy 13 and 18 as well as monosomy X, are anomalies associated with iniencephaly. Additionally, infants with iniencephaly have co-occurring additional anomalies, such as cleft lip and palate, gastrointestinal malformations, micrognathia, diaphragmatic hernias or cardiovascular disorders.

Diagnosing Iniencephaly

Diagnosis is made immediately after birth because an infant’s head is so severely bent backward that the face looks upward. In most infants, the neck is absent and the skin of the face is connected directly to the skin of the chest, while the scalp is directly connected to the skin of the back. Most infants with iniencephaly have additional birth defects, such as:

  • anencephaly (in which major sections of the brain fail to form)
  • cephalocele (in which part of the cranial contents protrudes from the skull)
  • cyclopia (in which the two cavities of the eyes fuse into one)

Additional birth defects include the lack of a lower jawbone or a cleft lip and palate. Other parts of the body may be affected, and infants can have cardiovascular disorders, diaphragmatic hernias and gastrointestinal malformations.

Treating Iniencephaly

The outlook for infants with iniencephaly is extremely poor. Newborns seldom survive much past childbirth. The distortions of the baby’s body also pose a danger to the mother’s life during delivery.

Iniencephaly is considered a rare disease, which often means there is not much information known about it. This is usually the case because doctors and researchers do not see many people with iniencephaly, which makes it hard to learn from them through observations or large studies.

Consider participating in a clinical trial so clinicians and scientists can learn more about iniencephaly and related disorders. Clinical research uses human volunteers to help researchers learn more about a disorder and perhaps find better ways to safely detect, treat or prevent disease.

Living with Iniencephaly

Parents who are planning a biological pregnancy who may be at high risk may consider genetic testing during early weeks following conception. Most of the babies are stillborn, and the others die within a few hours of birth. There are only six previously documented long-term survivors. In one case, our patient with iniencephalic signs and findings is still living. She is two years old now. We think that this patient presents a mild form of iniencephaly.

To further your understanding of your diagnosis and to contribute to cutting-edge research, consider participating in a clinical trial so clinicians and scientists can learn more about causes, symptoms, treatment and prevention. Clinical research uses human volunteers to help researchers learn more about a disorder and perhaps find better ways to safely detect, treat or prevent disease.

All types of volunteers are needed—those who are healthy or may have an illness or disease—of all different ages, sexes, races and ethnicities to ensure that study results apply to as many people as possible, and that treatments will be safe and effective for everyone who will use them.

For information about participating in clinical research, visit NIH Clinical Research Trials and You. Learn about clinical trials currently looking for participants at Clinicaltrials.gov.