KDM5C-related neurodevelopmental disorder: What to do next when your child has been diagnosed

What is a KDM5C-related neurodevelopmental disorder?

KDM5C-Related Neurodevelopmental Disorder is a rare condition caused by a "spelling change" in the KDM5C gene. This gene provides instructions for making a protein that plays an important role in many parts of the body, including how the brain develops, how genes are switched on and off, and how the body manages inflammation and energy.

When this gene change occurs, it can lead to differences in development, learning, and behavior. The features and severity of the condition can vary widely from person to person.

Another name you may see for this condition is Claes–Jensen syndrome. You might come across this term in medical records or scientific literature. This name refers to the same condition. However, some people with a KDM5C gene change, particularly females, may not receive this specific diagnosis since Claes-Jensen syndrome was originally characterized in males. Most affected males have Claes-Jensen syndrome and tend to be more severely affected. Females with KDM5C-related disorder have been reported to have milder features, including short stature, facial dysmorphisms, and mild intellectual disability.

Top resources for finding accurate medical information on a KDM5C-related neurodevelopmental disorder

Resources written for the general public

• NIH (Genetic and Rare Diseases Information Center): Syndromic X-linked intellectual disability Claes-Jensen type
• National Organization for Rare Disorders (NORD): KDM5C-Related Neurodevelopmental Disorder
• Genetics of Speech: KDM5C

Science-heavy resources targeted at clinicians:

• PubMed: KDM5C
• OMIM: KDM5C

Should I get a second opinion for a KDM5C-related neurodevelopmental disorder diagnosis?

Rare diseases require specialized expertise. Consider seeking a second opinion from a physician who focuses specifically on your child's condition. A fresh perspective can confirm the diagnosis, reveal additional treatment options, or simply provide reassurance about your care plan.

For many rare diseases, it can be hard to find a specialist with relevant experience. You can try asking providers you have seen, referring to community resources (see Section 5 below), or consulting a genetic counselor.

What does a genetic counselor do when my family has received a KDM5C-related neurodevelopmental disorder diagnosis?

Certified Genetic Counselors have completed a program of study focused on understanding and providing information about genetic disorders. A genetic counselor can help you understand the genetic aspects of your child's diagnosis, what it means for your family, and whether testing is recommended for siblings or other relatives.

Genetic counseling can take place in person or in a telemedicine visit. The National Society of Genetic Counselors offers a tool for finding a genetic counselor.

Should other family members undergo genetic testing for a KDM5C-related neurodevelopmental disorder?

KDM5C-related neurodevelopmental disorders are passed down in a pattern called X-linked inheritance, meaning the gene change is located on the X chromosome. Males who inherit this gene change are typically more severely affected, because they only have one X chromosome to begin with.

Females have two X chromosomes, so the picture can look quite different. In each of their cells, one X chromosome is randomly switched off, a process called X-inactivation (you may also see it called lyonization). Because of this randomness, females can experience a wider and more varied range of symptoms. Some females do show symptoms and some may have few or no noticeable features at all. This means a child can inherit the gene change from a mother who does not show any signs of the condition herself.

Females (XX chromosomes) with this condition have a 50% chance of passing the gene change on to each child. This breaks down to a 25% chance of having a son who is affected, and a 25% chance of having a daughter who carries the gene change but may not show symptoms herself.

In some cases, KDM5C-related neurodevelopmental disorders can also happen for the first time in a child, even when there's no family history of it. This is called a de novo change, meaning the gene change happened on its own rather than being passed down from a parent. When this is the case, the chance of having another child with the same gene change is usually low, under 1%.

Lastly, even if both parents test negative for the gene change in KDM5C, the recurrence risk is low (<1%), due to the small possibility of germline mosaicism, where the gene change is present only in a parent's sperm or egg cells.

What should I ask my child's specialists about a KDM5C-related neurodevelopmental disorder diagnosis?

Knowing what to ask can help you make the most of appointments with specialists. You can use these questions as a guide to discuss care that is specific to your child's diagnosis.

For questions specific to your child's situation, Citizen Health offers a free doctor's appointment preparation tool that incorporates your child's KDM5C-related neurodevelopmental disorder medical records and provides appointment preparation suggestions through an AI chat interface.

What symptoms should we monitor for a KDM5C-related neurodevelopmental disorder?

Every child with a KDM5C-related neurodevelopmental disorder will have their own unique experience. The list below shows some features that have been seen in many individuals with this condition, though not every child will experience all of these, and how much each one affects your child can vary:

• Delayed development (DD), including motor skills (e.g., delayed crawling or walking, or using their hands later than expected) and speech/language communication
• Autism, ADHD, and behavioral differences
• Intellectual disability
• Differences in muscle tone, such as muscles feeling softer or stiffer than usual
• Seizures
• Constipation and digestive differences
• Eye related issues (such as poorer close-up vision, called farsightedness)
• Being shorter than average
• Anxiety

Other features that have been reported:

• Strabismus, also known as crossed eyes, or farsightedness
• Feeding challenges
• A gradual weakening in their legs over time, which can affect how they feel sensations or move around.
• Some children share a few facial traits linked to this condition, like a softer jawline, a smaller chin, or slightly larger ears. These don't affect health or development and are simply part of your child's unique features.
• Trouble sleeping
• Feet that run small

What this looks like in females:

Most people with this condition are male (XY chromosomes), but females can have this condition too, generally with milder symptoms. When present, their traits often include some degree of developmental delay or learning differences (ranging from barely noticeable to moderate), slower language development, recognizable facial features, shorter stature, and behavioral traits like aggression, low tolerance for frustration, anxiety, and challenges in social settings.

What is the expected progression of a KDM5C-related neurodevelopmental disorder?

Symptoms of KDM5C-related neurodevelopmental disorders are known to typically appear in early childhood, but they can emerge at any age, which can impact the timing of diagnosis. Early signs often include delays in reaching developmental milestones, eye-related differences, seizures, or challenges with movement and muscle control.

There is a spectrum of presentation in females with KDM5C-related disorder, who may experience delayed speech and language development, often influenced by associated features like intellectual disability. However, males are expected to present with many of the features.

Current research aims to improve the understanding of KDM5C, with the hope of providing patients with more tailored clinical management and treatment (see the section on Finding Clinical Trial Opportunities & Supporting Research into KDM5C-Related Neurodevelopmental Disorder below for further details).

What treatments are available for a KDM5C-related neurodevelopmental disorder?

There is currently no cure for KDM5C-related neurodevelopmental disorders, but researchers are actively studying targeted therapies that may help in the future. For now, treatment focuses on managing symptoms and supporting your child's development, with care tailored to each individual's needs. Your child's doctor will work with you to find the right medication for their specific situation. See Section 3 for more on developmental therapies that can also help support your child.

The KARES Foundation keeps an updated page on their website with the latest research and potential treatments for this condition. If you'd like to dive deeper into the science behind this research, you can visit this link.

What healthcare providers should be on my child's care team for a KDM5C-related neurodevelopmental disorder?

Your child's KDM5C-related neurodevelopmental disorder care team is the group of providers who work together to support your child's health, development, and quality of life.

A KDM5C-related neurodevelopmental disorder affects multiple body systems, so your child's care team will likely extend well beyond a single doctor, and building it early matters, as waitlists for specialty and therapeutic services can be long.

Your team may include specialist physicians such as a gastroenterologist (digestive system), or orthopedist (musculoskeletal system), developmental pediatrician (growth and development), endocrinologist (hormones and growth), ophthalmologist (eyes and vision), neurologist (brain and nervous system), somnologists (sleep specialists) as well as a geneticist who can help manage the complexity of a rare disease diagnosis.

Therapeutic providers, such as a physical therapist (mobility and motor skills), occupational therapist (daily living skills and fine motor development), speech-language pathologist (communication and feeding), psychologist or neuropsychologist (cognitive and emotional support), or behavioral therapist (supporting emotional regulation and adaptive behavior), are equally important members, supporting your child's development, communication, and daily functioning. Ask your doctor which providers make sense for your child's specific needs. For a deeper look at therapeutic services and how to access them, see Section 3.

Finding clinical trial opportunities & supporting research into a KDM5C-related neurodevelopmental disorder

Families often want to know how they can stay informed about research related to KDM5C-related neurodevelopmental disorders. Research comes in many forms, ranging from studies that collect information about children's development (sometimes called "natural history" studies) to clinical trials that look at new approaches to care. Participation is entirely optional, and many families simply want to keep an eye on what opportunities exist. Advocacy groups often are great resources for learning about new clinical trial opportunities.

Citizen Health is tracking research about KDM5C-related neurodevelopmental disorders. If you are interested in personalized alerts about research studies, you can sign up to join the Citizen Health community.

When you participate in research, you help your child and other families in the future. Medical research studies can be very different from each other. Some test new treatments, while others are "natural history studies" that just collect information about a disease's impact over time.

Clinical trials are research studies that help doctors find new treatments. Some trials test new medicines or therapies that aren't available yet. Even if you may choose not to participate, it can be good to know what options exist for your child's condition. Your child's doctor or disease organization can help you find trials that might be a good fit. The U.S. government also maintains a registry at clinicaltrials.gov, where you can search "KDM5C" to see current trials underway or recruiting participants.

Natural history studies are designed to help researchers learn more about the condition. This information is important for creating future treatments. Traditional natural history studies can involve additional medical appointments over the course of several years.

Patient registries collect health information from people with specific diseases to help research move faster and connect families with clinical trials. Registries also show researchers and drug companies that families are engaged and want to help develop new treatments, which can bring more funding and research attention to a disease. Some diseases have more than one registry you can join. Patient Advocacy Groups typically establish and maintain patient registries for specific rare diseases. (See Section 5 below to learn more).

Organizing and maintaining your child's medical records for a KDM5C-related neurodevelopmental disorder

Rare disease patients see many different doctors, often across different medical and technological systems that may not talk to each other. Unfortunately, that means the burden often falls on caregivers to track care holistically, identify "gaps," and make sure nothing gets missed. Keeping your records as organized and centralized as you can from early on is likely to improve your ability to manage your child's care down the road.

You can start by creating a one-page sheet with your child's diagnosis, current medications, allergies, and emergency contacts. Bring this sheet to every appointment. It can really help in emergencies or when you see a new doctor.

Many caregivers establish one (or several) records binder(s) in which they keep track of appointments, medication updates, symptoms, and other ongoing medically relevant information.

We also encourage caregivers to consider Citizen Health's free tools for centralizing, managing, accessing, and extracting key information from health records. Our system will collect all your health records, across doctors and health systems, making them available on our secure online platform that can provide answers in real time based on questions you ask (like "What medications has my child been prescribed in the past year?" or "When did we last see an orthopedist?")

As a company built by rare disease caregivers, we aim to overcome the need for physical records binders. But ultimately the important question is what works for you and your family.

Before age 3: Understanding early intervention services for children with a KDM5C-related neurodevelopmental disorder

Early intervention provides therapies and support for children from birth to age 3 who have delays or disabilities. Services may include physical therapy, occupational therapy, speech therapy, and other developmental support. Speech and language delays are common and vary widely, from mild speech delays to limited or absent verbal communication, so therapy is often most effective when tailored to your child's specific needs. For children with little or no spoken language, introducing Augmentative and Alternative Communication (AAC) early on can help open up new ways to communicate. You can consider speaking with your speech-language pathologist about your child's communication style to find the best approach.

Every state has an early intervention program, and you can ask for an evaluation even if your child doesn't have a formal diagnosis yet. In some states, early intervention programs are called "birth to three", "early steps", or "first steps".

It's never too early to search for early intervention services in your state. Learn more from ECTA, the Early Childhood Technical Assistance Center.

3 & up: School services for children with a KDM5C-related neurodevelopmental disorder

IEPs and 504 plans

When your child turns 3, they move from early intervention to school-based services. An Individualized Education Program (IEP) is a legal document that describes the special instruction, therapies, and support your child needs to learn at school.

A 504 plan provides accommodations for students who don't need special instruction but need support because of a disability. Understanding your rights and these plans helps make sure your child gets the right services throughout their school years.

Communicating with your school

Building a good relationship with your child's school team is important. You know your child better than anyone, and that knowledge is incredibly valuable. Come to meetings prepared with information about your child's needs, share your concerns and hopes openly, and never hesitate to ask questions if something isn't clear.

Communication support is a key piece of this partnership. Children who are nonverbal or have limited speech may rely on AAC systems, and these are only effective if teachers, aides, and therapists use them consistently.

If your child has seizures, the school will likely keep a Seizure Action Plan on file, a document from your child's neurologist outlining what staff should do if a seizure occurs. Many states have specific laws about seizure management in schools.

You're an equal, essential member of your child's school team, and other KDM5C families can be a great resource for navigating communication support, seizure plans, and child's school experience.

Assistive devices and equipment for a KDM5C-related neurodevelopmental disorder

Depending on your child's needs, assistive technology and adaptive equipment can help with independence, communication, and quality of life. This might include communication devices (Augmentative and Alternative Communication or AAC), mobility equipment, positioning supports, or adaptive toys and tools. Your therapists can recommend the right devices, and many are covered by insurance or available through school programs.

Some devices and equipment can be expensive but can very often be covered by insurance. If coverage is denied, be sure to talk to your doctors about writing an appeal letter or a Letter of Medical Necessity. These documents can be critical for getting insurance coverage for devices and equipment.

Respite care

Caring for a child with complex medical needs is hard work, and taking breaks is important for your health and your family's wellbeing. Respite care provides temporary relief, giving you time to rest, handle other responsibilities, or just recharge. Options range from a few hours with a trained caregiver to overnight or weekend programs.

Respite isn't a luxury. It's a necessary part of taking care of your family long-term. The non-profit Access to Respite Care and Help (ARCH) provides guidance on how to find a respite care provider.

Building your support systems as a KDM5C-related neurodevelopmental disorder caregiver

Being a caregiver to a child with a KDM5C-related neurodevelopmental disorder is a heavy responsibility. You can't do it alone, and you don't have to. Building a network of support including family, friends, medical providers, therapists, other parents, and community resources, creates a safety net for hard days as well as people to celebrate victories with.

When asking for help, it helps to be specific: people want to support you but often don't know how. Whether it's meals, watching your other children, or just someone to listen, letting others help is good for everyone.

Don't forget about support for other family members! If your child has siblings check out the Sibling Support Project.

Medicaid and Social Security eligibility for a KDM5C-related neurodevelopmental disorder

Even if your family income exceeds typical Medicaid limits, children with KDM5C-related neurodevelopmental disorders may qualify for Medicaid through special pathways designed for those with disabilities or significant medical needs.

A program called Katie Beckett or TEFRA waivers allows children with disabilities to qualify for Medicaid based on their own income rather than family income. Additionally, children with significant functional limitations may qualify for Supplemental Security Income (SSI), which provides monthly payments and often automatically qualifies them for Medicaid. These programs can provide crucial coverage for therapies, equipment, and services private insurance won't cover.

Learn more about Medicaid in your state through this interactive map from NORD.

ABLE savings accounts for a KDM5C-related neurodevelopmental disorder

On that note, if your child qualifies for SSI, they may also be eligible for an ABLE (Achieving a Better Life Experience) account. ABLE accounts are tax-advantaged savings accounts specifically designed for people with disabilities that are opened in a child's name but do not count against the $2,000 asset limit that typically applies to programs like SSI and Medicaid. Find out more at ablenrc.org.

Understanding your insurance coverage for a KDM5C-related neurodevelopmental disorder

What's covered

• Your insurance policy determines what services, therapies, equipment, and medications are covered for your child. Start by reading your plan documents to understand your benefits, deductibles, co-pays, and out-of-pocket maximums. Call your insurance company's customer service or case management department as many insurers assign case managers to children with complex medical needs who can help you understand your coverage.
• Don't assume something isn't covered until you've asked. Many families are surprised to learn what benefits are available when properly documented.
• Keep notes of every call you make, including the date, time, person you spoke with, and what they said. This documentation can be very helpful later.
• Most children's hospitals also have a financial counselor or patient navigator who may be able to help with insurance or financial coverage issues.

Therapy & rehabilitation

• When considering insurance coverage for therapies and rehabilitation services, make sure to see if your plan has a cap for the number of therapy visits per year. Many children with complex needs will exceed that cap and appeals or additional insurance coverage plans may be needed.

Medical equipment

• If your child needs durable medical equipment such as a wheelchair, walker, orthotics, or at home equipment, getting insurance coverage for that equipment will likely require prior authorization or a letter of medical necessity.

Denials & appeals

• Insurance companies often deny coverage for therapies, equipment, or medications at first but denials can often be overturned with the right documentation. If coverage is denied, you have the right to appeal, and many families win their appeals.
• An effective appeal letter includes: your child's diagnosis and how it affects their daily life, specific medical reasons from doctors explaining why the service or item is necessary, references to your insurance policy language that supports coverage, research or medical guidelines supporting the treatment, and a clear request for reconsideration. Many patient organizations and hospital financial counselors can help you write strong appeals. You can even appeal multiple times, and many families win on their second or third attempt. You're advocating for your child, and persistence often pays off.

Non-discrimination protections for a KDM5C-related neurodevelopmental disorder

The Genetic Information Nondiscrimination Act (GINA) is a federal law that protects you from genetic discrimination in health insurance and employment. Health insurance companies cannot use genetic information to deny coverage, raise your premiums, or determine eligibility. However, GINA does not cover life insurance, disability insurance, or long-term care insurance. Employers cannot use genetic information when making hiring, firing, or promotion decisions. Understanding these protections can give you confidence in pursuing genetic testing and sharing results with your child's healthcare providers without fear.

Learn more about these protections from the American Society of Human Genetics.

Why connect with other KDM5C-related neurodevelopmental disorder families?

Finding and connecting with families who have walked in your rare disease shoes can be life-changing. Other parents navigating the same diagnosis can offer practical advice, emotional support and hope based on their shared experience. They can understand the daily challenges and the victories, big and small, in ways that others can't. Disease-specific communities often become a lifeline and a source of hope that remind you that you are not alone.

Local KDM5C-related neurodevelopmental disorder support groups

Your genetic counselor or other healthcare provider may be able to connect you with local families in your area. It is totally appropriate to ask your providers if they know of any local families who might be willing to connect with you for a phone call or even a play date.

Some rare diseases are so exceptionally rare that it might not be possible to connect locally with another person with the same rare disease. But collectively, rare diseases are not that rare! Connecting with broader rare disease groups is another great option. Many states and communities have organizations that support all rare diseases.

Patient advocacy groups (PAGs) specific to a KDM5C-related neurodevelopmental disorder

Patient advocacy groups exist for many rare diseases and serve as a central hub for connections, reliable information, research updates and advocacy efforts. These organizations work to advance research, improve care standards, raise awareness, and support families. They often host conferences, maintain family directories or registries, fund research, provide educational resources, and fight for policies that benefit the community.

Connecting with your disease's advocacy organization gives you access to experts, researchers, and a network of families while contributing to the larger mission of finding treatments and cures.

The KARES Foundation is an organization dedicated to advancing research and understanding of KDM5C-related neurodevelopmental disorders, while providing a warm and supportive community for those navigating a KDM5C-related neurodevelopmental disorder diagnosis. Learn more about KARES here.

There are lots of resources online to help you find a patient advocacy group!

• https://www.simonssearchlight.org/
• https://globalgenes.org/rare-list/
• Search on Facebook — many PAGs organize in Facebook Groups

If your rare disease does not have a specific patient advocacy group, you can even start your own! Every rare disease, even the rarest and smallest, can benefit from a coordinated effort from a patient advocacy group. Multiple Citizen Health team members have founded patient advocacy groups for their children's disorders, including our Co-Founder Nasha Fitter, who discussed her takeaways from the experience on an episode of the Once Upon a Gene podcast.

The National Institutes of Health has produced this resource for caregivers considering starting an advocacy group.

Disease-specific conferences and events

Many patient advocacy groups will help spread awareness through conferences and events. These can include in person events or online events and are great opportunities to connect with others and to stay on the cutting edge of new research opportunities.

Attending a conference focused on your child's condition can be transformative. These gatherings bring together families, researchers, doctors, and advocates in one place. You'll hear about the latest research, learn from medical experts, meet families at different stages of the journey, and let your child connect with others like them.

Many families describe their first conference as the moment they felt less alone. While attending may require travel and expense, many organizations offer scholarships or financial assistance to help families participate. If you can go, it's often worth it.