Carpenter syndrome is an extremely rare genetic condition. In these patients, the bones that make up the skull fuse together too early. New-born infants and children normally have soft spaces between the main bones of the head. These initially allow the baby’s head to fit through the mother’s birth canal during birth. After birth, they allow the child’s brain to grow properly. This is one of the reasons a baby’s head circumference is routinely measured during doctors’ appointments.
Normally, the soft bones will harden and fuse together during the first 18 months of life. In children with Carpenter syndrome, the soft spaces between the bones fuse together before the child is born. The fusion can occur in only one or in several of the spaces of the head.
Carpenter Syndrome is extremely rare and only about 70 cases are known. Because of this, it is difficult to study.
There are two subtypes based on the location of the faulty gene causing the syndrome:
The early fusing of a child’s head can cause the child’s skull and face to appear pointed or misshapen. Some other associated symptoms include:
The severity of these symptoms varies from patient to patient and even between affected members of the same family. Not all patients will show all symptoms.
Carpenter syndrome is caused by a faulty gene on either chromosome 6 or chromosome 19. Carpenter syndrome type 1 is associated with the gene on chromosome 6. Carpenter syndrome type 2 is associated with the gene on chromosome 19.
Every person inherits two sets of 23 chromosomes from each parent. To get Carpenter syndrome, a person must inherit the faulty gene from both parents. It appears that males and females are affected equally.
Most children are diagnosed at birth or shortly afterward. Doctors may request routine blood tests or imaging to determine what is causing the baby’s symptoms. Because the symptoms of Carpenter syndrome are like those of other diseases, it can take some time to make the diagnosis.
Genetic testing that shows the typical faulty genes is the final diagnostic tool. This is usually a blood test. As with all genetic testing, the patient and family members should speak with a genetic counsellor prior to having the test.
Unfortunately, there is no cure for Carpenter syndrome. Treatment aims to correct a patient’s symptoms. Potential options include:
Patients with Carpenter syndrome usually require a team-based approach to treatment. Team members may include:
Complications of Carpenter syndrome vary from patient to patient because of the differences in disease severity. Some patients become independent adults. Others require support throughout their lives. Associated heart disease can shorten the lifespan.
If a person knows they are a carrier of the gene for Carpenter syndrome, they and their partner should consider genetic testing prior to attempting to conceive.