Jesy Nelson and SMA Type 1’s Twins: Everything You Asked This Week

I took over Jesy’s Insta story the last week of vacation. Asking viewers to stop and watch, she gave an update on her twin babies’ condition, although it was one of the rawest and most deeply personal I’ve seen in a long time.

Jesy Nelson’s twins were diagnosed with Type 1 Spinal Muscular Atrophy (SMA). The diagnosis was not easy. In fact, their journey began when Jesy’s mother observed a lack of lower body movement early on and a struggle to get support ever since. The news immediately sparked concern, curiosity and countless online searches.

It’s understandable. SMA type 1 is a condition that most people only encounter when it enters their lives directly – through pregnancy, a newborn, or family history. Although the diagnosis may seem frightening, current treatments and support systems offer a hope and quality of life unimaginable just ten years ago.A

Here we answer the new and big questions you have about SMA type 1 – as individuals, parents or parents-to-be – from inheritance and symptoms to specific treatments, charities and resources.

What are the types of SMA?

SMA is not a single condition, it exists on a spectrum. Understanding types can help give some context – here’s a quick overview:

Type 1 (Werdnig-Hoffmann disease)

The most severe form – and the condition affecting Jesy Nelson’s twins – presents during infancy, often before six months.

Babies may have muscle weakness, poor head control, difficulty feeding and breathing. Without intervention, SMA Type 1 historically life expectancy limited to early childhood. However, this is changing with advances in diagnosis and treatment.

Type 2

Symptoms appear later in infancy or early childhood. Children can sit but cannot stand independently. Life expectancy is longer than that of type 1 and many live into adulthood with proper care.

Type 3 (Kugelberg-Welander disease)

SMA beginning in childhood, lighter, with the ability to walk, although mobility may decrease over time.

Type 4

SMA beginning in adulthood. Muscle weakness is usually mild and life expectancy is generally normal.

Understanding type is essential because prognosis, treatment and daily care differ significantly. For example, SMA Type 1 is limiting life without treatmentwhile type 4 can go unnoticed for years.

What causes SMA Type 1 and is it inherited?

SMA Type 1 is a genetic disease caused by mutations in the SMN1 genewhich produces a protein vital for the survival of motor neurons (the nerve cells that control voluntary muscle movements). Without enough SMN protein, motor neurons gradually die, leading to muscle weakness and a gradual loss of mobility.

SMA is inherited in a autosomal recessive modelwhich means both parents must be carriers of the defective SMN1 gene. Carriers generally have no symptoms.A

If both parents are carriers, there are:

• 25% chance the baby has SMA
• 50% chance the baby is a carrier
• 25% chance the baby will not be affected

Many families only discover they are carriers during pregnancy or after birth.

How is SMA type 1 diagnosed?

Early diagnosis is essential.

During pregnancy, SMA can be detected by chorionic villus sampling (CVS) or amniocentesis if the parents are known carriers or if there is a family history. Routine ultrasounds cannot detect SMAalthough certain subtle signs can arouse suspicion.

In the United Kingdom, Neonatal screening is being rolled out in several regions, offering the opportunity to begin treatment before symptoms appear. Early detection of SMA is transformative, as the most effective treatments are targeted to genes and work best before motor neuron loss occurs.

What are the first signs of SMA type 1 in infants?

Babies with SMA type 1 usually have symptoms first six months of lifeincluding:

• Flexibility or low muscle tone
• Weak or absent head control
• Difficulty swallowing or eating
• Shallow breathing or use of abdominal muscles
• Limited movement of arms and legs

Although SMA itself is not painful, secondary complications such as joint stiffness, respiratory infections or fatigue, can cause discomfort that can be managed with multidisciplinary care.

Is SMA type 1 fatal and what is the life expectancy?

Historically, SMA type 1 was considered fatal in early childhood. However, the landscape has changed dramatically with gene therapies and SMN-stimulating drugs.

• Children receiving early treatment can now survive well beyond early childhood, with some reaching school age and adolescence.
• THE oldest documented individuals with type 1 have exceeded previous life expectancy predictions thanks to proactive and comprehensive care. One of the most famous is an activist Steve Mikitadied at the age of 67 after being diagnosed at the age of one.

This change highlights that Type 1 SMA is now considered a treatable disease, not an incurable one.particularly when diagnosed and treated early.

What treatments are available for SMA Type 1?

Treatment focuses on targeting the genetic root and supporting the body’s functions.

Gene therapy

• Onasemnogene abeparvovec (Zolgensma) is a single intravenous infusion replacing the defective SMN1 gene.
• It is most effective when given before symptoms appear.
• Available on the NHS for eligible patients.

NMS-enhancing drugs

• Nusinersen (Spinraza): Spinal injection administered periodically.
• Risdiplam (Evrysdi): Daily oral medication.

Both work at increase SMN protein productionslowing or stopping the progression of the disease.

Supportive care

Beyond medications, infants and children benefit from:

• Physiotherapy to maintain movement and prevent contractures
• Respiratory assistanceincluding non-invasive ventilation
• Nutrition assistance such as nasogastric or gastrostomy tubes
• Specialized equipment for mobility and daily life

A NHS multidisciplinary team Typically supervises these interventions, including neurologists, physical therapists, respiratory specialists, and dietitians.

Can SMA Type 1 be cured?

Currently there is no outright curebut the treatments are spectacular modify disease progressionimprove quality of life and prolong survival. Early access to gene therapy or NMS-modulating drugs gives families hope where there was none before.

How does SMA affect families, pregnancy and parenting?

Expectant parents who discover a high risk of SMA may face complex decisions. Genetic counseling, carrier screening, and careful pregnancy planning are key resources.

Pregnancy is still possible, but families must plan for delivery, neonatal care, and continued treatment. High-profile cases like that of Jesy Nelson bring important awareness: they highlight the real experiences behind the medical facts and the importance of early diagnosis.

For parents, daily life involves navigating therapies, equipment and possible hospital admissions. It also includes moments of joy, milestones, and advocacy, if that works for you.

Resources, Charities and Blogs

Support extends well beyond the clinic. The UK has a vibrant network of SMA charities and foundations:

SMA United Kingdom

It is the UK’s leading spinal muscular atrophy charity. SMA United Kingdom offers family support, advocacy, equipment financing and awareness campaigns. The Jennifer Trust became SMA Support UK in 2013.

SMA Foundation (international)

The mission of Spinal Muscular Atrophy Foundation is to accelerate the development of treatments against SMA. Their focus is research, clinical trials and global advocacy.

August is SMA Awareness Month – note and monitor highlights, advances in diagnosis, treatment and research. The efforts of charities, foundations, families, patients and medical teams have made it possible to:

• Lobby for universal newborn screening
• Funds access to gene therapy and clinical trials
• Support family-centered care

Awareness campaigns also inform the public that SMA does not in itself mean a specific life expectancy or lifestyle.

Key takeaways

SMA type 1 is a serious genetic disease, but modern medicine has transformed results. Families now have access to:

• Early diagnosis thanks to prenatal and neonatal screening
• Life-changing treatments like gene therapy and NMS-enhancing drugs
• Multidisciplinary physiotherapy, respiratory assistance and feeding assistance
• Community support via blogs, social media, charities and patient networks

High-profile stories, like the one unfolding for Jesy Nelson’s twinshighlights the challenges and triumphs of living with SMA Type 1, helping to raise awareness and encouraging families to seek help as soon as possible.

On your reading list: Elsie Hewitt on conceiving with endometriosis – highlight an underdiagnosed chronic illness.