Symptoms & Lifespan Journey: What to Expect

Knowing what to expect can help you move from a state of uncertainty to a state of readiness. While 15q13.3 microdeletion syndrome affects everyone differently, there are common “themes” that tend to appear at different stages of life.

The Childhood Years: Building a Foundation

In early childhood, the focus is often on supporting physical and cognitive development. Most children with this syndrome have very few dysmorphic features (physical differences in appearance), meaning they generally look like other children in their family ^[1][2].

Movement and Development

Many infants and young children experience hypotonia, or low muscle tone ^[1]. This may make them feel a bit “floppy” when held and can lead to delays in reaching milestones like sitting up, crawling, or walking. While waiting for official physical therapy referrals, you can safely encourage movement at home with supervised and modified “tummy time.” Early physical and occupational therapy are often very effective in helping children gain strength and coordination ^[3].

Learning and Behavior

Developmental delays and intellectual disability (ID) can range from very mild to moderate ^[1]. Many children also show signs of Autism Spectrum Disorder (ASD) or ADHD ^[3]. Early intervention—such as speech therapy and specialized educational support—is the cornerstone of management during these years.

“Staring Spells”: Childhood Absence Seizures

One of the most common medical symptoms in 15q13.3 microdeletion is a specific type of epilepsy called absence seizures ^[4].

• What they look like: These are often called “staring spells.” Your child may suddenly stop what they are doing, stare into space for a few seconds, and then resume their activity as if nothing happened.
• What to do: If you suspect a staring spell, try to record it on your smartphone. Video evidence is incredibly helpful for the pediatric neurologist.
• Management and Safety: These seizures require careful medical management. It is completely normal if it takes trying a few different medications to find the one that works best ^[4]. Crucially, while medications are being adjusted, unmedicated staring spells pose a safety risk. You must exercise caution and supervise your child closely during activities like swimming, bathing, bike riding, or crossing the street.

Nutrition and Weight

Some children with this deletion, especially those missing the CHRNA7 gene, may have an increased risk for rapid weight gain or obesity ^[5]. Establishing healthy routines and clear boundaries around food early on can help manage this risk.

Adolescence and Adulthood: Navigating New Risks

As children move into their teenage years and beyond, the clinical focus often shifts from physical milestones to mental health and psychiatric well-being.

Neuropsychiatric Risks

Research indicates that individuals with a 15q13.3 microdeletion have an increased risk (approximately 10 times higher than the general population) for developing schizophrenia or other forms of psychosis in late adolescence or early adulthood ^[6].

Psychosis is a medical term for when a person has trouble distinguishing what is real from what is not. While this can be a scary prospect for parents, it is important to contextualize this risk:

• Understanding the Numbers: The general population risk for schizophrenia is about 1%. A 10-times higher risk means the risk is around 10%. This also means there is a 90% chance your child will never develop it. Because of incomplete penetrance, many adults with this deletion never develop these conditions ^[7].
• Modifiable Triggers: High levels of psychological stress and the use of illicit substances (especially heavy cannabis use during adolescence) are known environmental triggers for psychosis in genetically vulnerable individuals ^[8]. Educating your teen about these specific risks is a proactive step you can take.
• Anticipatory Guidance: Knowing the risk allows for “anticipatory guidance.” This means you and your child’s doctors can watch for early signs (like social withdrawal or unusual changes in thinking) and intervene with therapy or medication much sooner, which significantly improves long-term outcomes ^[3][9].

By staying observant and maintaining a strong relationship with a neurology or psychiatry team, you can provide the support your child needs as they transition into adulthood.