Kyphoscoliotic Ehlers-Danlos syndrome (kEDS): signs, diagnosis and care

The Ehlers-Danlos syndromes are a group of inherited conditions affecting connective tissue, which provides support in skin, tendons, ligaments, blood vessels, internal organs and bones. The NHS says there are 13 types, most of them rare, and lists kyphoscoliotic EDS among the main types alongside hypermobile, classical and vascular EDS.

The Ehlers-Danlos Society describes kEDS as a heritable connective tissue disorder that causes low muscle tone, early-onset kyphoscoliosis and joint hypermobility, and one that also increases the risk of life-threatening arterial dissection and rupture. Kyphoscoliosis is a combination of kyphosis, a forward rounding of the upper back, and scoliosis, a sideways curve. The Society notes that in kEDS it is often present at birth or develops in early childhood and is usually severe and progressive.

kEDS is caused by genetic variants in the PLOD1 or FKBP14 genes. The Society explains that it is inherited in an autosomal recessive pattern: a person has changes in both copies of the gene, one from each parent. Parents are typically carriers who do not themselves have kEDS. People with kEDS will always pass on one changed copy to their children, who will only be affected if they also inherit a second change in the same gene from the other parent.

The NHS explains in general terms that, depending on the type of EDS, the faulty gene may have been inherited from one parent or both. The practical implication for families is that genetic counselling, which the NHS says can help you learn how the condition is inherited and the chances of passing it on, is particularly relevant in recessive types such as kEDS.

The Society lists the key signs: congenital or early-onset kyphoscoliosis, low muscle tone (hypotonia), joint hypermobility, delayed motor development, eye problems including blue sclerae, refractive errors and ocular fragility, foot deformities such as clubfoot and flat feet, soft, stretchy or fragile skin, easy bruising and, in FKBP14-kEDS, hearing loss. The NHS description is consistent: spinal curvature starting in early childhood and often worsening in the teenage years, loose joints that dislocate easily, weak muscle tone from childhood that may delay sitting and walking, fragile eyes that can be easily damaged, and soft, velvety, stretchy skin that bruises and scars easily.

Other features the Society lists include arterial aneurysm, dissection and rupture, which can affect major and minor arteries including the aorta, low bone density, hernias, pectus deformity and, in some people, bladder diverticula. It warns that features differ between people.

• Medical emergencies named by the Society include arterial dissection or rupture, and globe rupture of the eye.

• Muscle atrophy and follicular hyperkeratosis are reported in FKBP14-related kEDS.

• Most children with kEDS eventually walk independently, although this can be delayed.

The Society sets out the diagnostic criteria: a person must meet major criterion 1 and 2 and 3, or criteria 1 and 2 plus three minor criteria. The major criteria are congenital muscle hypotonia, congenital or early-onset kyphoscoliosis and generalised joint hypermobility with dislocations or subluxations, particularly of the shoulders, hips and knees. Minor criteria include skin hyperextensibility, easy bruising, rupture or aneurysm of a medium-sized artery, osteopenia, blue sclerae, hernia, pectus deformity, marfanoid habitus, clubfoot and refractive errors. If the criteria are met, genetic testing should be done to confirm the diagnosis.

In the UK, the NHS says a GP can refer you to the local genetics service if one of the rare types is possible, where a genetics specialist assesses the medical and family history and may carry out a genetic blood test. If further investigation is needed, a hospital doctor can refer to a specialist EDS diagnostic service based in Sheffield or London.

The Society's guidance is that kEDS is managed by addressing the symptoms a person has and that care usually involves several specialties, with a focus on the musculoskeletal system, skin and cardiovascular system. The NHS says there is no specific treatment for EDS but that many symptoms can be managed with support and advice, and that regular scans may be used in certain types to detect problems with internal organs.

Typical members of the team include physiotherapy and occupational therapy to protect joints and function, orthopaedic and spinal surgeons for curvature, eye specialists, cardiologists or vascular specialists for the arteries, audiology for hearing in FKBP14-kEDS, and genetics. Because the Society calls arterial dissection and rupture and globe rupture medical emergencies, people with kEDS should be told what symptoms need 999 or A&E and carry information for treating teams.

The Society's page also lists pregnancy-related features reported when the baby has kEDS, including reduced fetal movements, preterm premature rupture of membranes and brain haemorrhage in the fetus or newborn, so anyone planning a pregnancy should involve genetics and obstetric specialists early. Carrying a clear summary of the diagnosis helps any treating team that has not met kEDS before.

The NHS route runs from GP to genetics service and the national specialist EDS diagnostic services, with local rheumatology, orthopaedic, ophthalmology and cardiology follow-up. Ehlers-Danlos Support UK is the UK charity that provides information and an advice line for all EDS types.

A private opinion is sometimes sought for faster assessment, but with such a rare condition the national NHS diagnostic services hold much of the expertise. Ask any clinician how they will coordinate with your NHS team, and keep copies of genetic reports.