Acampomelic campomelic dysplasia (ACD) is a rare genetic syndrome. A form of campomelic dysplasia, ACD has the same features, except for bowing of the long bones. Features of the syndrome become apparent prenatally, or just after birth. ACD can be very severe at birth; problems with breathing and an unstable upper spine that can cause death. It is estimated to affect every one in 40,000 to 80,000 individuals, according to "GeneReviews."
Features
Babies with ACD have characteristic facial features that include a very small chin and a specific form of cleft palate called "Pierre Robin." In addition, they often have only 11 ribs instead of 12. Other features include short upper arms and legs and clubbed feet. Many males born with ACD have female-looking or ambiguous external genitalia. A specific test that looks at a person's chromosomes is needed to determine if a female-looking baby is genetically a boy or a girl. Respiratory complications and an unstable spine are the most serious features of ACD as these are life-threatening.
Diagnosis
ACD can be suspected during pregnancy. An ultrasound performed in the second and third trimester, routinely looks at a baby's bones allowing clinicians to detect the short long bones. Once the baby is born, a doctor can diagnose the baby by physical features and X-rays. Genetic testing for a gene, called SOX9, that is associated with ACD, can confirm the diagnosis in some cases. Other genetic changes in the chromosomes may also be present. However, not every child with ACD will have identifiable genetic changes. Intelligence is normal and some children with ACD have short stature.
Management
According to "GeneReviews," the first steps after diagnosis is genetic testing. One test looks at the SOX9 gene to see if changes are present. The other test will look at the chromosomes to see if the baby has male or female chromosomes. Children with ACD often have hearing problems, therefore hearing tests are recommended. Surgery to treat cleft palate, spinal instability and other features of ACD may be needed. Other medical interventions are needed depending on specific features of an individual.
Genetics
Even though ACD is a genetic disorder, most cases occur sporadically. Every so often, a new genetic change occurs in the very early stages of embryo formation. If this new genetic change occurs in the right place, such as in the SOX9 gene, it can cause ACD. However, a family that has had one affected child has a higher chance over the general population for a second affected child. According to the American Journal of Medical Genetics, if a couple has previously had a child with ACD, the chance they will have another affected child is about five percent for each pregnancy. Individuals who are affected with ACD have a 50 percent chance for having a child with ACD.
Support
Having a child with a serious medical condition is very stressful on families. Stress can stem from difficulties managing a child's care, paying for medical costs, and balancing normal daily life. Sometimes, unaffected siblings of children with genetic diseases can act out in a way to attract their parent's attention. Finding effective coping mechanisms for all member of the family is important. Some people find it helpful to speak with others who have been though similar experiences. There are many different support and advocacy associations available, such as The Little People of America and Mothers United for Moral Support (MUMS).
References
- GeneReveiws: Campomelic dysplasia
- "American Journal of Medical Genetics"; Acampomelic Campomelic Dysplasia; Ute Moog; 2001
- "A Guide to Genetic Counseling"; Diane Baker; 1998
