How Is Apert Syndrome Diagnosed?
Apert syndrome is a rare genetic condition that occurs when the sutures, or joints, in a baby’s skull close earlier than they should during fetal development, resulting in distinct physical characteristics. Apert syndrome, also known as acrocephalosyndactyly, can often be recognized through these physical characteristics. A baby with apert syndrome will have a skull that is taller than normal and can appear pointed at the top, which is known as acrocephaly. The backside of the skull is usually very flat and the forehead will often be high or broad. Babies with apert syndrome will have eyes that are widely spaced on the face and may show signs of bulging or slanting down. Babies with Apert syndrome may also have a flat or beak-like nose, and the face will often be asymmetrical. While these physical characteristics may be recognizable to doctors who have experience with the syndrome, there are still tests that must be done in order to diagnose Apert syndrome in a baby or child. The Special Olympics Arizona team is breaking down this diagnosis: what tests may be necessary to diagnose after birth, and what tests may be done to diagnose a baby in utero.
Apert Syndrome Diagnosis
An apert syndrome diagnosis is most commonly made at birth or during early infancy. Apert syndrome symptoms include physical features such as facial anomalies consistent with those of Apert syndrome or syndactyly. These can be identified early and may be indicators to individuals who recognize the symptoms and believe that a child should undergo the series of specialized tests and clinical evaluation necessary to make a diagnosis. Tests to diagnose Apert syndrome include:
Medical X-rays are common types of tests that are used to generate images of tissues and structures inside the body. An X-ray is a form of electromagnetic radiation, similar to light, but with a higher energy that can pass through most objects, allowing the X-rays to travel through the body and pass through a detector on the other side of the body, allowing images to be created of the objects and structures inside the body. X-rays will be used on the spine, arms, hands, and legs to observe the structure of these body parts in a baby and confirm an Apert syndrome diagnosis based on the images provided by the X-ray machine.
Computed Tomography (CT) Scan
A CT, or computed tomography, scan is a machine that will combine a series of X-ray images taken from different angles around the body and use computer processing to create cross-sectional images of the bones, blood vessels, and soft tissues in the body. These cross-sectional images, or slices, can be used to provide more information on the internal structure of a baby with Apert syndrome and help doctors determine the best course of treatment for the child. CT scans can also be used throughout treatment for apert syndrome to monitor bone growth before, during, and after any treatments to monitor progress, as well as to check for hydrocephalus and raised intracranial pressure, if necessary.
If your child has the physical characteristics of Apert syndrome, they will likely undergo genetic testing to determine if the FGFR2 gene is mutated, which will confirm the diagnosis. FGFR2, the fibroblast growth factor receptor 2, is a gene that plays an important role in the formation of bones during fetal development, and a mutation of this gene is the cause of Apert syndrome. Apert syndrome can be inherited, or it can be a mutation that occurs in a baby with no familial history, but genetic testing will allow doctors to confirm the diagnosis and help determine a course of action moving forward.
Diagnosing Apert Syndrome Before Birth
In some instances, a baby can be diagnosed with Apert syndrome while in utero. If you have a family history of apert syndrome or other genetic syndromes that you have made your doctor aware of, it is likely you may undergo tests during pregnancy to determine if your baby is at risk for apert syndrome or other inherited syndromes. These tests may include:
Prenatal 2D or 3D Ultrasound
A prenatal ultrasound is a test that all mothers undergo throughout their pregnancy that allows doctors to view the shape and position of a baby in utero. This test is safe and painless and uses sound waves to create images showing a baby. A 2D ultrasound is commonly done twice throughout pregnancy, once during the first trimester to confirm the due date and a second time around 18-22 weeks to confirm normal anatomy and discover the sex of the baby. Some doctors will offer a 3D ultrasound, which provides a three dimensional view of the baby in utero. During these ultrasounds, a doctor will be checking the baby for normal anatomy and fetal development, and if they notice any anomalies, they may take another ultrasound or conduct further testing to determine if your baby has Apert syndrome.
Magnetic Resonance Imaging (MRI)
A fetal MRI is a noninvasive imaging test that offers detailed information about the anatomical structures of the fetus and can provide clear, high-resolution images. An MRI uses a magnetic field, rather than radiation, to obtain pictures for evaluation. If a physical anomaly consistent with Apert syndrome is recognized on a prenatal ultrasound, a doctor may refer you for a fetal magnetic resonance imaging test so they can obtain higher-resolution images that can supplement the information obtained during a prenatal ultrasound. A fetal MRI can be performed during the 2nd or 3rd trimester and can be used to evaluate abnormalities in the brain, spine, and body of a baby. MRI’s are commonly used to confirm a diagnosis or add significant information in complex cases.