NKAP-related Syndrome

NKAP-related syndrome is a genetic disorder that causes developmental delays, intellectual disabilities, behavioral problems and musculoskeletal abnormalities. The disorder may cause people with the disorder to grow taller than their peers and have bone and joint problems. NKAP-related syndrome only affects males.

NKAP-related syndrome has only recently been identified. It’s likely that the condition is underdiagnosed, but with testing, more cases may be confirmed.

NKAP-related syndrome is caused by a mutation in the NKAP gene. In some cases, the gene mutation is inherited from the mother in an X-linked recessive fashion. In most cases, the gene mutation associated with NKAP-related syndrome is simply a random mutation and is new in the person who develops the syndrome.

The NKAP gene is known to help blood and immune cell development. But it likely also plays an important role in brain and musculoskeletal development given the developmental and intellectual delays, as well as joint and bone problems of those with the syndrome. Research is ongoing to learn more about the function of the NKAP gene.

Children with NKAP-related syndrome have developmental disabilities and may behave aggressively. Other signs and symptoms may include:

• Tall stature
• Neuromuscular scoliosis, or curvature of the spine
• Low muscle tone Joint contracture — limited range of motion in the joints
• Very long fingers
• Heart defects

NKAP-related syndrome may be diagnosed through a physical exam and a thorough review of your child’s and family’s medical history. Your child’s doctor may order a genetic test to confirm a diagnosis of NKAP-related syndrome.

Because there is no cure for NKAP-related syndrome, your child will be referred to specialists at CHOP to manage their symptoms. Your child may be seen by specialists in Developmental and Behavioral Pediatrics, the Division of Orthopaedics and the Cardiac Center. The specialists will work with you and your child to develop plans to help your child live as healthy a life as possible

CHOP geneticist Kosuke Izumi, MD, PhD, was the first to identify NKAP-related syndrome, putting CHOP at the forefront of research into this condition. At CHOP, children with NKAP-related syndrome have access to the nation’s top pediatric specialists and coordinated care for medical and developmental problems related to this diagnosis.