Prader-Willi Syndrome Symptoms In Infants

What is Prader-Willi syndrome?

Prader-Willi Syndrome (PWS) is a rare genetic disease that affects about 1 in 10,000 to 1 in 15,000 people worldwide.¹ It affects all races and sexes equally. There are thousands of people living with PWS at any given moment, each of them facing a wide range of issues and living their own unique story. The disease causes several behavioural and neurological issues that start during infancy and continue throughout childhood and adulthood. Genetic researchers are working hard to unravel the mechanisms of PWS.²

Although the cause is not fully understood, genetic changes in chromosome 15 are likely to be the main culprits. Many of the symptoms are the result of the incorrect development and function of the hypothalamus and pituitary gland. These parts of the brain regulate hormones and other important functions such as appetite.^3,4 Scientists are still trying to figure out which specific genes in chromosome 15 are responsible for PWS. They believe that a better understanding of the genetic causes may allow for improved treatments and management strategies to be developed.

Although there is no cure yet, the symptoms of PWS can be managed to a degree if they are spotted early in a person’s life. This early diagnosis can pave the way to specialised and targeted care that dramatically improves quality of life and leads to better outcomes in childhood and adulthood. 

Prader-Willi syndrome often reveals itself during infancy in the form of a few suggestive signs and symptoms. It is vital that these early indicators are recognised so that parents and caregivers can obtain a quick and accurate diagnosis for the baby. Below, the main early signs and symptoms of PWS are explored. These can occur from before birth up to around two years of age, after which a different set of challenges often emerges.

Early symptoms of Prader-Willi syndrome (in utero and shortly after birth)

Symptoms of Prader-Willi syndrome in utero

Even before a baby is born, there are a few clues that they might have PWS. Expectant mothers sometimes notice that their baby is moving significantly less than expected in the womb compared to more typical pregnancies. This lack of movement is the result of hypotonia (muscle weakness) which is one of the main symptoms of PWS.⁵ Ultrasound scans and other common forms of testing are unlikely to provide any obvious evidence of PWS in these early stages, making arriving at a definitive diagnosis very challenging.

Childbirth for babies with Prader-Willi syndrome

Although not necessarily a sign or symptom of PWS in isolation, babies with PWS are more often born through cesarean section or require assisted delivery methods compared to their healthy counterparts. Although babies with PWS are usually within the normal range for fetal size, their birth weight and body mass index are about 15% lower than their healthy siblings.⁵

Symptoms of Prader-Willi syndrome in infancy

Immediately after birth, the tell-tale signs of PWS become more obvious. Babies with PWS often have a set of symptoms that define the disease and are not expected in healthy babies. It is important to note that a diagnosis is usually confirmed through genetic testing, without which these early signs could be the result of different diseases. The most important of these early signs are:

• Hypotonia: Also known as muscle weakness, this is one of the most obvious symptoms in babies with PWS. Although the obvious signs of hypotonia are floppy limbs, it affects the entire physical response system of the baby.³ These babies often show signs of reduced reflexes and movement in general, in addition to poor posture
• Problems with feeding: Muscle weakness often affects the lips and makes the babies unable to suck and swallow properly during feeding.^2,3 This affects their ability to latch during breastfeeding. The entire process of feeding can be very tiring for babies with PWS as it requires much more effort than it does for a healthy baby. During early infancy, this lack of proper feeding can cause delayed growth and even weight loss, which can be what prompts parents to seek medical advice
• Facial abnormalities: Some babies with PWS have noticeable facial features that are characteristics of the disease.¹ These include almond-shaped eyes, a narrow forehead and a downturned mouth. It is important to note that these features can be seen in healthy babies and are not a definitive sign of PWS. Only when in the context of other signs and symptoms are they meaningful and can aid in providing a diagnosis

As babies develop over the first few months of their lives, they may begin to show other signs that suggest PWS:

• Failure to thrive: During the initial few months of the baby’s life, they might struggle to gain weight or grow normally, even if they are able to feed properly³
• Delays in development: There are certain milestones used to measure and assess a baby’s development, such as rolling over, lifting the head, smiling, and so on. In babies with PWS, developmental delay is usually more pronounced later in childhood, but they may still fail to reach these milestones as expected³

Recognising these early signs of PWS is vital because without proper medical advice and targeted intervention, it becomes difficult to prepare for the many changes and challenges that occur later in life which are discussed below. In fact, scientists believe that there could be many people living with PWS who were never diagnosed. These people could have a better understanding of the challenges they face and more effective ways of coping if they had been given the correct medical advice.

Managing Prader-Willi syndrome symptoms in infancy

A variety of specialists are involved in managing the symptoms of babies with PWS and educating parents on how to properly care for their infant.⁶ Genetic counselling is usually recommended once the symptoms are noticed and a diagnosis has been made. Genetic counselling aims to educate parents and caregivers about the disease and how it will affect their child’s life.

Dieticians play a key role in managing the feeding issues that many infants with PWS struggle with. The goal is to make sure that the baby receives enough calories even if breastfeeding is a struggle. Usually, this is done by adding additional calories to a bottle feed or, in extreme situations, using a tube.³

Additional steps are usually taken, including physical, occupational, and speech therapy from an early age. The idea is that by being proactive and taking steps early, it becomes more possible to address physical weaknesses, feeding problems and communication skills further down the road.

There is ongoing research into the best ways to improve the lives of people with PWS.⁷ These include hormone therapies to improve hypothalamic and pituitary function and pharmacological interventions to help with the symptoms that mainly impact the quality of life.⁸

Families are usually given support in the form of groups, comprehensive care planning, and regular contact with specialists in the disease.¹ A diagnosis of PWS can be overwhelming for families at first, so it is important that they are given regular input from different experts so that they feel prepared for the challenges ahead. It is important to note that the symptoms of PWS evolve as the child develops. At around age two, the issues of muscle weakness and underfeeding evolve into a completely different set of problems marked by overeating, obesity and its various complications. Counselling plays an important role in preparing parents for these changes.

Summary

The journey of people with Prader-Willi Syndrome is challenging. The symptoms experienced in infancy can be distressing for parents and must be recognised if the baby is to receive the best care. The outcomes of people with PWS can be improved with early intervention, underscoring the importance of being proactive and seeking expert medical advice if these signs and symptoms are noticed. Although the current treatment options aim to control symptoms, there is hope that future developments in hormone therapy will provide ways to improve the development of children with PWS and allow them to live more normal, healthy lives.