An inherited blood disorder is what we often know as something that “runs in the family.” It is passed down from one or both parents to a child.

Inborn errors of metabolism are a diverse group of disorders caused by an inherited deficiency or defect in a single enzyme or protein. Your body needs these vital enzymes and proteins. When there are not enough of them, the body cannot break down certain large molecules correctly. As a result, a harmful amount of these large molecules, or “storage materials,” builds up and damages organs and body systems.

People with inborn errors of metabolism often develop nerve deterioration. These disorders may also impair the heart, vision, hearing, bone growth, lungs, and muscles. Children with these disorders may need multiple surgeries and restricted activities. They may also have growth problems and persistent discomfort.

At MSK Kids, we understand how devastating it is to hear your child has one of these serious disorders, and we know you want to do everything you can to give your child the best life possible. That’s why we put together one of the most experienced teams in the country to diagnose inborn errors of metabolism early and assemble a treatment plan to minimize the organ damage and discomfort they can cause. We also work with other researchers close to home and around the world to share knowledge and better understand these illnesses so we can improve the lives of more children and families.

X-Linked Adrenoleukodystrophy (X-ALD)

X-ALD is a rare genetic disorder that only affects males. The genetic defect impairs the body’s ability to break down certain fats, causing them to build up in the body. This affects how the adrenal glands, testes, and central nervous system work. The myelin sheath — the layer of insulation that protects nerves in the body — breaks down, causing nerve cells to lose their ability to work. About 40 percent of boys with ALD experience this disorder in the brain, called cerebral ALD (cALD). Early signs of the problems include hyperactivity, poor school performance, and a short attention span.

The only effective treatment for cALD is a stem cell transplant before the disease becomes too advanced. Early diagnosis and monitoring are therefore very important. The team at MSK Kids has extensive experience caring for children with cALD, offering stem cell transplantation and monitoring. We continue to refine the treatment of these young men to improve their outcomes. We are also interested in evaluating gene therapy as a possible treatment. We will let you know if your child is able to participate in a clinical trial. The decision to enroll is entirely voluntary.

Metachromatic Leukodystrophy (MLD)

Metachromatic leukodystrophy (MLD) is a rare inherited disorder in which a missing enzyme leads to a buildup of a fat called sulfatide in the body. The myelin sheath — the layer of insulation that protects nerves — breaks down, causing nerve cells to lose their ability to work. Children who develop MLD between the ages of 6 months and 2 years have what is called late infantile MLD. They may show a change in gross motor skills, such as walking. They may also lose their ability to speak, move, or swallow.

Children with juvenile MLD begin to show symptoms between ages 4 and 12 — such as problems walking or standing up straight, emotional difficulties, trouble following directions, and poorer school performance.

Adult MLD arises as early as the teen years and may be misdiagnosed as a mental health issue because the person may develop personality changes, anxiety, and an impaired memory.

Treatment is possible for juvenile and adult MLD. A stem cell transplant is the only known cure and should be done before the disease becomes too advanced. Early diagnosis and monitoring are therefore very important. A donor’s healthy cells provide a continual supply of the missing normal enzyme. The team at MSK Kids has extensive experience caring for children, teens, and young adults with MLD, offering stem cell transplantation and monitoring. We also continue to refine the treatment of these young patients to improve their outcomes. We’ll connect your child with any other specialists they may need. We are also interested in evaluating gene therapy as a possible treatment. We will let you know if your child is eligible to participate in a clinical trial. The decision to enroll is entirely voluntary.

Hurler Syndrome (Mucopolysaccharidosis Type 1)

Also known as mucopolysaccharidosis type 1 (MPS-1), Hurler syndrome happens when an enzyme needed to break down certain long chains of sugar molecules is missing. The sugars build up in many tissues in the body, which causes life-threatening organ damage. Most children with Hurler syndrome begin to show symptoms between the ages of 1 and 2, such as frequent colds and ear infections; noisy breathing; changes in bone growth and facial features; vision and hearing problems; mental retardation; and issues affecting the heart, liver, and spleen. Treatment with a stem cell transplant early in life is the only way to stop the disease from progressing. A donor’s healthy cells provide a continual supply of the missing normal enzyme, halting organ damage.

At MSK Kids, our team has a lot of experience caring for children with Hurler syndrome. We work hard to diagnose the illness early and perform a stem cell transplant as soon as possible. We also understand that children with Hurler syndrome have unique medical needs, and we’ll connect you with other necessary specialists, such as neurologists and neuropsychologists, endocrinologists, cardiologists, pulmonologists, and orthopedists. Together, your child’s care team creates a personalized monitoring and treatment plan to achieve the best possible results.

Other Inborn Errors of Metabolism

The MSK Kids team works together to diagnose these disorders and start treatment as early as possible. Children with these inborn errors of metabolism have access to our expertise in stem cell transplantation, the only effective therapy. They may also be able to participate in a clinical trial of novel gene therapies. The decision to enroll in a clinical trial is entirely voluntary.