The manifestations of XLH exhibit significant variability and typically become apparent around eighteen months after birth.

In babies, you might observe an unusually elongated and narrow head shape (dolichocephaly), an increased front-to-back dimension of the skull (scaphocephaly), or premature fusion of skull bones (craniosynostosis).

In families where there is no history of XLH, the diagnosis journey can often be challenging. A diagnosis and treatment plan will be created once your baby is referred and seen by a paediatric endocrinologist.

Burosumab is recommended for treating XLH in children with radiographic evidence of bone disease aged 1 year and over, and in young people with growing bones.

Burosumab was licensed in Europe in February 2018, with the National Institute for Health and Care Excellence in England first recommending the use in October 2018. Therefore, this can be prescribed on the NHS in England, Wales, Scotland, HSC in Northern Ireland and the NCPE in the Republic of Ireland. The prescription and treatment plan is managed by a paediatrician once the diagnosis is confirmed.

In people with XLH, the hormone fibroblast growth factor 23 (FGF23) is overactive, which signals to decrease the phosphate in the blood, resulting in poor bone mineralisation. Burosumab (marketed as Crysvita) is a monoclonal antibody that suppresses the activity of fibroblast growth factor 23 (FGF23). By suppressing FGF23, burosumab normalises the phosphate levels in the blood, which aids normalising bone mineralisation.

Burosumab is administered via subcutaneous injection, typically every 2-weeks for children. The British Paediatric and Adolescent Bone Group (BPABG) recommend that the starting dose is 0.4 mg/kg. After commencing treatment, blood phosphate levels are typically monitored every 2 weeks during the first month, every 4 weeks for the following 2 months and thereafter as appropriate. Treatment can begin in children aged 1 year and can continue until the bones stop growing.

Reference: Padidela R, Cheung MS, Saraff V, Dharmaraj P. Clinical guidelines for burosumab in the treatment of XLH in children and adolescents: British paediatric and adolescent bone group recommendations. Endocr Connect. 2020 Oct;9(10):1051-1056. doi: 10.1530/EC-20-0291. PMID: 33112809; PMCID: PMC7707830.

Transition between paediatric and adult care is the planned movement of young adults with chronic conditions from child-centred healthcare to adult-oriented systems. This process usually occurs between ages 14 and 18 to prepare patients and their families for the transfer of care. However, many XLH patients experience different levels of transition and face an uncoordinated transfer of care.

During this transition period, mental and emotional difficulties can arise, leading to confusion about care arrangements, especially when it coincides with major life changes like leaving home for work, university, or travel. Adult healthcare systems are often coordinated differently to paediatric care, requiring young-adult patients to take responsibility for accessing and managing their care from sometimes multiple specialists.

We recommend that young-adult patients take extra care to ensure that they remain in the NHS/HSE system once they are released from paediatric care.

We suggest that adults with XLH be seen at regular intervals by multidisciplinary teams organised by an expert in metabolic bone diseases. The symptoms and complications of XLH vary widely from patient to patient; so treatment and monitoring should be tailored to the patient based on their symptoms, medical history, stage of development and the clinician’s professional judgement.

The clinician should liaise with the patient’s local health-care providers, such as the GP, radiologists, orthopaedic surgeons, physical therapists, rheumatologists and dentists. In addition, the following professions might be involved based on individual patient needs: neurosurgeons, otolaryngologists (ENTs), ophthalmologists, orthodontists, dieticians, chiropodists, social workers and psychologists.

For adults with symptoms like musculoskeletal pain, pseudofractures, dental issues, or biochemical signs of weak bones (osteomalacia), treatment is recommended. The current standard treatment involves taking active vitamin D and phosphate supplements, which can help reduce pain and improve bone health.

Taking the supplements can be challenging for some people and can have serious side effects including gastrointestinal distress, diarrhoea, kidney stones, nephrocalcinosis, and hyperparathyroidism. It is essential to maintain your appointments with your clinical expert to mitigate side effects while getting the most out of available treatment.

For certain orthopaedic problems, surgery might be necessary in addition to medical treatment to correct bone deformities and treat fractures.

Remember, it’s essential to work closely with your healthcare provider to find the best treatment plan for you or your loved ones.

Pain experienced because of XLH varies from person to person and over time, but drug treatments and other therapies can help you cope. Drugs alone are not usually the answer, partly because their usefulness has to be balanced against side effects. If you can describe pain well, both to health professionals and those around you, there is more chance it can be managed.

Musculoskeletal pain is the pain in muscles and joints that comes from living with the stresses and strains XLH places on the body. It can be acute (starts suddenly, but then gets better or goes away) or chronic (ongoing, long-term pain that never completely goes away). You may be asked to rate the intensity of pain on a ten-point scale, where 1 is negligible and 10 is overwhelming. Try to record if there are specific activities or movements that trigger pain episodes.

Keeping a pain diary has lots of benefits, it lets you share with your doctor details about your symptoms, which you may otherwise forget.

Analgesic painkillers: Drugs like paracetamol, aspirin, ibuprofen, and codeine can help control pain. Opioids such as tramadol are occasionally used for acute pain.

Transcutaneous Electrical Nerve Stimulation (TENS) This is a way of providing short-term pain relief that involves a small, battery-operated machine. Stimulation of the nerves can disrupt pain signals going to your brain and spinal cord and can relax your muscles. 

Acupuncture You can get acupuncture through some GP surgeries, pain clinics and physiotherapists. It comes from ancient Chinese medicine, and involves sticking fine needles into specific points on your body. This makes your body release its own natural pain killers. You can use acupuncture to treat migraines and musculoskeletal problems like back pain.

Hypnotherapy A professional hypnotherapist can lead you into a deeply relaxed or ‘hypnotised’ state and suggest how you can improve how you feel when you come out of it. You can’t normally get hypnotherapy on the NHS. Find qualified, insured hypnotherapists who are registered with a professional body here

Chiropractic A registered practitioner (chiropractor) uses their hands to help relieve problems with your bones, muscles and joints.

Osteopathy A registered practitioner (osteopath) uses their hands to move, stretch and massage your muscles and joints. 

Massage and reflexology (where pressure is put on specific areas or ‘zones’ of your feet and hands) can both be effective at releasing tension in muscles and associated pain.

Pain clinics: specialise in helping you find ways of coping, managing and adapting to living with pain. They’ll help you lessen its impact on your quality of life. 

Occupational therapy: there may be adjustments that can be made to your living or working space that help to reduce pain. Ask your employer for an assessment.

Mindfulness meditation offers a different way of approaching and thinking about your pain. There’s a special eight-week programme called ‘mindfulness-based stress reduction’ for people with chronic pain. It’s taught by instructors in hospitals. There’s a free online version (with audio meditation tracks that you can follow) here

Cognitive Behavioural Therapy (CBT) is a talking therapy, sometimes available on the NHS. You can get it on a one-to-one basis with a professional psychotherapist, or participate in a group or online. CBT is now frequently recommended to manage chronic pain and fatigue. Because pain affects thoughts, feelings, behaviours and physical reactions, CBT works with the idea that these are closely connected and influence each another. You can find a list of registered therapists through the Association of Psychotherapists.