Miller-Dieker Syndrome: Causes, Symptoms, and Treatment
Medically reviewed by Harsha Moole, MD, Internal Medicine. Last reviewed: October 23, 2026.
What kind of doctor treats Miller-Dieker Syndrome?
A pediatric neurologist (a doctor for brain and nerve problems in children) and a geneticist (a doctor for inherited conditions) usually lead care for Miller-Dieker syndrome. A direct primary care or concierge doctor can be a first stop for an evaluation and can refer you to a specialist when needed.
What is Miller-Dieker syndrome?
Miller-Dieker syndrome is a condition marked by a pattern of abnormal brain development called lissencephaly. Normally, the surface of the brain has folds and grooves. Lissencephaly makes the surface abnormally smooth, with fewer folds and grooves.
It appears to be rare, but the exact number of people with it is unknown. It is also called Miller-Dieker lissencephaly syndrome.
Symptoms
In people with this syndrome, lissencephaly is typically linked with severe intellectual disability, developmental delays, weak muscle tone, and seizures. Seizures usually begin in the first few months of life.
Many people also have distinctive facial features, which can include:
- A prominent forehead.
- A sunken look in the middle of the face.
- A small, upturned nose.
- Low-set ears with an unusual shape.
- A small jaw.
- A thick upper lip.
Some people grow more slowly than their peers. Less often, people have heart problems or kidney abnormalities. Some have an omphalocele, an opening in the wall of the abdomen that lets organs poke out through the navel.
Causes and who gets it
In most cases, Miller-Dieker syndrome is caused by a missing piece of DNA near the end of the short arm of chromosome 17. The size of the missing piece varies, but it typically includes the PAFAH1B1 and YWHAE genes.
Losing the PAFAH1B1 gene causes the lissencephaly seen in this condition. Losing the YWHAE gene is thought to make the lissencephaly more severe. In about 10 percent of people with the signs of the syndrome, the cause is unknown.
In most cases, it is not inherited, which means it is not passed down from a parent. The deletion is usually a random event. It happens when egg or sperm cells form, or early in the baby's development.
Some people inherit a chromosome change from a parent who has no health problems. That parent carries a balanced translocation, a swap of DNA between chromosomes in which no DNA is gained or lost.
How doctors diagnose it
Miller-Dieker syndrome is linked to deletions that include both the PAFAH1B1 and YWHAE genes. A test called chromosomal microarray can find large missing or extra pieces of DNA, such as these deletions.
For the related condition PAFAH1B1-related lissencephaly, doctors suspect it from clinical findings and brain MRI scans.
Treatment
Expert care advice exists for a related condition, PAFAH1B1-related lissencephaly. That advice leaves out Miller-Dieker syndrome. Ask your child's doctors what fits your child.
For that related condition, experts advise treating seizures promptly and strongly, because poor seizure control often lowers function and health. Treatment uses anti-seizure medicine matched to the type and number of seizures.
Feeding therapy can help with poor weight gain. A feeding tube placed into the stomach may be needed for lasting feeding or breathing problems.
For young children, experts recommend early intervention. This program offers occupational, physical, speech, and feeding therapy.
When to see a doctor
Seizures need prompt treatment, so tell your child's doctor right away if seizures start or get worse.
Call 911 or go to the emergency room if your child has a seizure that lasts longer than 5 minutes, has another seizure soon after the first one, has trouble breathing or waking up after a seizure, has bluish or grey skin, or is very hard to wake.
How a direct primary care or concierge doctor fits in
A direct primary care doctor charges a flat monthly fee instead of billing insurance, while a concierge doctor usually charges more and often works alongside insurance. Either type of doctor can help your family get the referral to an early intervention program that experts recommend for young children.
Common questions
Is Miller-Dieker syndrome inherited?
Usually not. In most cases, Miller-Dieker syndrome is not inherited. Some people inherit a chromosome change from a parent who has no health problems.
Does Miller-Dieker syndrome affect intelligence?
Yes, it can. Lissencephaly in this condition is typically linked with severe intellectual disability and developmental delays.
What is lissencephaly?
Lissencephaly is a pattern of abnormal brain development. The surface of the brain is abnormally smooth, with fewer folds and grooves.
How long do people with Miller-Dieker syndrome live?
Most people do not survive beyond early childhood. Many children die within the first two years, and only a few reach age ten. Each child is different, so ask your child's doctors what to expect.
Sources
- MedlinePlus Genetics - Miller-Dieker syndrome
- GeneReviews (NCBI Bookshelf) - PAFAH1B1-Related Lissencephaly / Subcortical Band Heterotopia
- CDC - First Aid for Seizures
Medical Disclaimer
This content is for general educational and informational purposes only and is not medical advice. It is not a substitute for professional medical advice, diagnosis, or treatment, and reading it does not create a doctor-patient relationship. Always seek the advice of your physician or another qualified health provider with any questions about a medical condition, and never disregard or delay seeking professional advice because of something you read here. If you think you may have a medical emergency, call 911 (or your local emergency number) immediately.
