Understanding Phelan-McDermid Syndrome: Benji and Giulietta’s Journey

Phelan-McDermid Syndrome (PMS), also known as 22q13 deletion syndrome, is a rare genetic condition caused by the loss or dysfunction of the SHANK3 gene, along with other genes essential for building neural networks. SHANK3 plays a vital role in brain development, and its absence is one of the known genetic causes of autism spectrum disorder (ASD).

While PMS affects each individual differently, Benji and Giulietta share this genetic diagnosis but experience it in their own unique ways.

With Phelan-McDermid Syndrome, challenges rarely exist in isolation. Low muscle tone, sensory processing differences, and proprioceptive difficulties all interact and influence one another. These interconnected factors contribute to learning differences, communication barriers, and overall developmental delays.

Sensory Processing

Sensory processing is how our brains register, interpret, and respond to the world around us. For individuals with PMS, neural signals may not process sensory information in a consistent or organized way. This can lead to delayed responses, difficulty focusing, or trouble completing tasks.

Benji and Giulietta both show an under-responsive sensory profile, meaning it often takes them longer to notice or react to sensory input. They may seem less responsive to sound, touch, or movement even when their brains are working hard to interpret those signals.

Physical Challenges

A hallmark of PMS is low muscle tone, which affects both gross and fine motor skills as well as overall endurance. Imagine an elastic band that has lost its tension, movements require extra effort and energy.

This condition also interacts with dyspraxia, a motor planning difficulty that affects movement coordination, judgment, and memory. Despite these challenges, Benji and Giulietta have shown remarkable persistence and growth. With consistent hands-on practice and creative support, they continue to build strength, coordination, and confidence in daily life activities.

A Body-Based Approach

To support their development, we have built a body-based approach into their daily routines. These activities focus on proprioception, the body’s sense of position and movement, and help regulate energy levels through active muscle engagement. By closely observing Benji and Giulietta’s body language, we can tell when they need rest, when to encourage them gently, and how to keep their nervous systems balanced.

Communication

Although Benji and Giulietta are non-verbal, they have powerful ways to communicate. Through Augmentative and Alternative Communication (AAC) systems, picture cards, and visual supports, they express their thoughts, feelings, and needs.

Proprioception

Proprioception is our internal sense of where our body is in space. Receptors in the muscles and joints constantly send signals to the brain, allowing smooth and confident movement without needing to look at every motion.

For Benji and Giulietta, proprioceptive awareness does not always come naturally. Activities that build this sense, such as pushing, pulling, climbing, and deep-pressure exercises, help their bodies become more aware of movement.