Peirson Center for Children

11/18/2025

Why does folinic acid need to be given in high doses when folate receptor antibodies (FRA) are present?

It comes down to two things:
affinity (how strongly a receptor attracts folate)
and density (how many of those receptors exist in the area that transports folate into the brain).

1. Folate Receptor Alpha (FRα)

FRα is located on the apical (top) membrane of the choroid plexus, the gateway responsible for transporting folate into the cerebrospinal fluid (CSF).

FRα has:
🔸 Extremely high affinity for methylfolate (a very strong magnet)
🔸 High receptor density - meaning lots of these receptors are packed tightly on the choroid plexus surface
🔸 A direct route into the CSF

But when folate receptor antibodies are present, they block or disable this entire high-affinity, high-density transport system.

When FRα is blocked, the brain loses its main entry door for folate.

2. Reduced Folate Carrier (RFC)

RFC provides a secondary pathway, but it’s nowhere near as efficient.

RFC has:
🔹 Very low affinity for folate (a weak magnet)
🔹 Much lower density compared to FRα at the blood-CSF barrier
🔹 A location that is not well-positioned for transporting folate into the CSF (mainly basolateral side of choroid plexus + neurons/glia)

This means RFC is open, but it’s not strong enough or abundant enough to transport folate into the brain at normal physiological levels. It’s like the side door to the brain - narrow, inefficient, and not designed for the main flow of folate.

So why high-dose folinic acid?

Because with FRα blocked:

➡️ Only the low-affinity RFC pathway is left
➡️ RFC cannot “grab” folate unless blood levels are extremely high
➡️ High-dose folinic acid floods the system
➡️ Allowing a small amount to pass through RFC and reach the brain

This is why children with FRA often need high-dose folinic acid, sometimes 1-2 mg/kg or more, to restore healthy folate levels in the CNS.

11/17/2025

🌟 New Blog Post! 🌟
“From Food to Brain: The Long Journey of Vitamin B12”

Vitamin B12 plays a key role in your child’s energy, development, behavior, and brain health, yet most people don’t realize how complex its path is inside the body. Even when a child eats well or has “normal” labs, B12 may not be getting where it needs to go.

In this new article, I walk through:
✨ The two critical enzymes that rely on B12
✨ Signs and symptoms of deficiency in children
✨ Every barrier B12 has to cross - from digestion to the brain
✨ Why serum levels don’t tell the whole story
✨ The most accurate tests to evaluate B12 status
✨ The connection between folate and B12
✨ How to support healthy B12 delivery in the body

If you have a child with Down syndrome, autism, developmental delays, fatigue, speech challenges, or neurological symptoms - this one is especially for you. 💛

Read the full post here:

https://www.peirsoncenter.com/articles/from-food-to-brain-the-long-journey-of-vitamin-b12

11/14/2025

Dr. LaRosa and Dr. Peirson are attending the LymeBytes Symposium virtually this weekend, and the lectures so far have been absolutely fascinating and deeply clinically relevant.

They’re always learning, always evolving, and always looking for new ways to better support their patients, especially those navigating complex chronic infections, immune dysregulation, and neurodevelopmental challenges.

Staying on the cutting edge of research helps us bring the most thoughtful, evidence-informed care back to our families.

If you're curious about the event, you can learn more here:

LymeBytes!™

11/12/2025

🌿We’re thrilled to welcome Dr. Hayleigh Ast, ND to the Peirson Center for Children! 🌿

👩‍⚕️Dr. Ast brings a deep dedication to helping children and young adults reach their fullest potential through integrative, evidence-based care. Her clinical focus includes supporting children with Down syndrome, autism, ADHD, and other neurodevelopmental conditions, always honoring the powerful connection between the brain, body, and gut.

🩺Dr. Ast trained under Dr. Erica Peirson, an experience she describes as profoundly impactful in shaping her approach to pediatric neurodevelopment and functional medicine. Through this mentorship, she gained advanced understanding of mitochondrial health, methylation, and the biochemical individuality of children with Down syndrome and autism, foundations she now brings to her own clinical practice.

🧒She is especially passionate about addressing the impact of diagnostic overshadowing, where medical or behavioral concerns are too often overlooked or attributed solely to a diagnosis. Dr. Ast is committed to seeing the whole child, their strengths, challenges, and unique biology, to uncover what truly supports their growth and thriving.

🔬A licensed naturopathic physician and post-doctoral fellow at Oregon Health & Science University, Dr. Ast has contributed to multiple peer-reviewed studies on the gut-brain-immune axis and micronutrient therapies for ADHD and other pediatric conditions.

✨ Dr. Ast will begin seeing patients in early December! We’re honored to have her join our team and continue advancing our mission of empowering families and supporting children to truly thrive now and into the future. 💛💙

11/03/2025

Not all folate is the same.

Folate is an umbrella term for a family of vitamin B9 compounds that drive critical reactions in the body, including DNA synthesis, methylation, detoxification, and neurotransmitter production.

🟩 Methylfolate (5-MTHF) - This is the biologically active form of folate. It donates methyl groups to convert homocysteine to methionine, fueling the SAMe cycle that powers methylation of DNA, neurotransmitters, and phospholipids. Methylfolate also supports BH4 regeneration, a cofactor essential for producing dopamine, norepinephrine, and serotonin. People with MTHFR variants (C677T or A1298C) often rely more heavily on supplemental methylfolate.

🟨 Folinic Acid (5-formyl-THF, or Leucovorin) - A naturally occurring, metabolically active form that does not require MTHFR for conversion. It readily converts to 5,10-methylene-THF, supporting purine and pyrimidine synthesis, the building blocks of DNA and RNA. Folinic acid can cross the blood–brain barrier even in the presence of folate receptor antibodies, making it especially important for individuals with FRα autoimmunity or cerebral folate deficiency.

🟦 Folic Acid - The synthetic, oxidized form used in fortified foods and many supplements. It must be converted to dihydrofolate (DHF) and then tetrahydrofolate (THF) by the DHFR enzyme, which has limited activity in humans. When intake exceeds conversion capacity, unmetabolized folic acid (UMFA) can accumulate in the blood and may interfere with natural folate transport or immune signaling.

These biochemical distinctions explain why one form of folate doesn’t fit everyone. Supporting the right step of the pathway can optimize methylation, cognition, and cellular repair, especially for those with MTHFR variants or folate receptor antibodies.

© Infographic by Peirson Center for Children

www.peirsoncenter.com

10/31/2025

As Down Syndrome Awareness Month wraps up, let’s take a closer look at just how much extra genetic material is involved in Down syndrome and what that really means.

Chromosome 21 makes up only about 1.5-2% of all the genetic material that makes us who we are. The region on chromosome 21 that is most associated with the key traits of Down syndrome, called the Down Syndrome Critical Region (DSCR), accounts for roughly 37% of that chromosome.

That means this critical region represents just 0.56-0.74% of the entire human genome. So while chromosome 21 adds a little extra, the other 99.2-99.5% of their DNA carries everything that makes them unique and far more like their own family than like anyone else with Down syndrome.

Although this small stretch of DNA has far-reaching implications, it doesn’t explain everything we see in our loved ones with Down syndrome. The way these genes are expressed varies widely among individuals and across different tissues. Other genes, regulatory feedback, and environmental influences all interact to shape each person’s development, health, and abilities. Understanding this complexity reminds us that genetics is never one-dimensional, and that the potential within every person with Down syndrome is truly endless.



www.peirsoncenter.com

10/30/2025

As Down Syndrome Awareness Month comes to a close, we're reflecting on what makes every individual truly unique - not just in personality, but in biology.

Not every person with Down syndrome looks, develops, or responds to interventions the same way and science helps explain why.

Research shows that the effects of trisomy 21 are shaped by each person’s unique genetics and environment. Other inherited alleles and external influences modify how those extra genes are expressed, creating a wide range of outcomes across individuals.

🧬Beyond Trisomy 21: Phenotypic Variability in People with Down Syndrome Explained by Further Chromosome Mis-segregation and Mosaic Aneuploidy
https://pmc.ncbi.nlm.nih.gov/articles/PMC5837063/

Even within the same person, gene expression differs from tissue to tissue. It isn’t a simple 1.5× increase in activity for every triplicated gene. Expression is regulated by complex feedback systems that adjust levels dynamically.

🔬 The importance of understanding individual differences in Down syndrome
https://pmc.ncbi.nlm.nih.gov/articles/PMC4806704/

Recognizing this variability helps us avoid diagnostic overshadowing, the tendency to attribute every medical or behavioral concern to the diagnosis itself. When we look deeper, we see opportunities for personalized care that supports every child and adult with Down syndrome to truly thrive.



www.peirsoncenter.com

10/23/2025

🔍 Common Myths About Folinic Acid (Leucovorin)

Let’s clear up a few myths about folinic acid (leucovorin). We see a lot of confusion online, especially mixing it up with MTHFR, methylfolate, or general ‘folate support.’ In reality, this therapy is specifically aimed at restoring brain folate transport in children who have blocking antibodies to folate receptors.

“It’s for MTHFR mutations.”
Fact: Folinic acid doesn’t correct MTHFR enzyme issues. Its role is to bypass blocked folate receptors and restore folate transport into the brain. The MTHFR gene affects methylation of folate inside cells, while folate receptor antibodies block brain uptake. They’re two completely different pathways.

“It’s the same as methylfolate.”
Fact: Folinic acid and methylfolate are completely different molecules. Folinic acid supports intracellular folate cycling and brain folate transport, while methylfolate donates methyl groups in cytosolic methylation reactions.

“Everyone with autism or Down syndrome needs it.”
Fact: Only those with folate receptor alpha autoantibodies (FRAA) or signs of cerebral folate deficiency truly benefit. It’s not a one-size-fits-all therapy.

“It’s a vitamin, so you can’t overdo it.”
Fact: Folinic acid acts pharmacologically at high doses. The research doses (1-2 mg/kg/day up to 50-100 mg/day) are therapeutic, not nutritional, have the potential for significant side effects and should be monitored by an experienced physician.

“It’s safe to start on your own.”
Fact: Dosing and tolerance vary widely. Some children become more stimulated, anxious, or aggressive initially, so experienced medical guidance is essential.

“If it didn’t work at a low dose, it won’t help.”
Fact: Many clinical responses occur only at higher, physician-managed doses (up to 2 mg/kg/day or more), especially in FRAA-positive cases.

“You don’t need testing - just try leucovorin and see.”
Fact: While some children respond clinically, testing matters. Knowing whether folate receptor antibodies are present helps determine if brain folate transport is blocked and whether high-dose folinic acid is likely to help. It also avoids unnecessary or confusing supplement trials.

“A negative FRAT result means folinic acid won’t help.”
Fact: Not necessarily. Some children test negative but still respond, likely due to other transport or mitochondrial issues. However, a positive result strengthens the rationale for treatment.

“Leucovorin works on its own. You don’t need anything else.”
Fact: Many children do better when leucovorin is paired with key cofactors such as B12, lithium, and calming supports to help mitigate potential side effects.

Used correctly and under medical supervision, leucovorin can be transformative for language and cognition in some children, but it’s not for everyone. It’s powerful, precise, and should always be guided by testing and clinical context.

10/22/2025

🌿 What’s in the air & on the skin matters

We all love our homes to smell fresh, our lotions to feel nice, and our personal-care products to have a pleasant scent. But what if those fragrances and scented products were influencing more than just the sense of smell? Recent research suggests they could be influencing puberty in children.

Here’s what the science says

A 2024 study by the National Institutes of Health (NIH) found that certain fragrance molecules, like musk ambrette, which is used in soaps, detergents, and lotions, activated hormone-receptor pathways in human and animal lab models. Specifically, they triggered receptors that sit in the brain’s puberty-control centre.
https://www.nih.gov/news-events/nih-research-matters/certain-chemicals-may-trigger-early-puberty-girls

Another paper (2022) reviewed how exposure to endocrine-disrupting chemicals (EDCs), including phenols, phthalates and parabens commonly found in personal-care and household products might be linked to shifts in puberty timing.
https://pmc.ncbi.nlm.nih.gov/articles/PMC9742306/

A 2019 clinical case-series found that in children using lavender-oil scented products (soaps, lotions, diffusers), breast development or prepubertal breast-changes resolved after discontinuing the scented products. The authors also showed that components of the oils had estrogenic (and anti-androgenic) effects in lab assays.
https://pmc.ncbi.nlm.nih.gov/articles/PMC6773459/

Why this matters

Early (or altered) puberty isn’t just about starting growth earlier: it’s been associated with higher risks later in life (e.g., heart disease, diabetes, some cancers), as noted the 2024 study above.

Children’s bodies are especially vulnerable. Their hormone systems are developing, and small exposures can have bigger-than-expected effects.

Scented products and fragrances are everywhere: lotions, soaps, shampoos, diffusers, laundry detergent, scented candles, etc. Sometimes the label just says “fragrance”, which may mask dozens of chemical ingredients.

What you can do to reduce potential exposure

Choose fragrance-free or “unscented” products (and be cautious that “unscented” may still hide masking scents).

Read labels for “fragrance,” “parfum,” “perfume”. If they’re present, ask whether they disclose ingredients (often they don’t).

Use simpler products: plain soap, plain shampoo, minimal lotions.

Ventilate your home: open windows, use fans instead of relying solely on scented air fresheners/diffusers.

For the youngest kids, consider avoiding scented baby products and find more natural-ingredient alternatives.

Small changes add up. By choosing fragrance-free products, you’re protecting your child’s hormones and supporting a healthier puberty timeline. Our kids’ bodies are listening. Let’s give them the cleanest signals possible.

10/14/2025

💙💛 Down Syndrome Awareness Month: From Awareness to Action

Children with Down syndrome have unique gifts that shape families and communities in profound ways.

Supporting individuals with Down syndrome medically isn’t about changing who they are. It’s about helping them thrive.

Children with Down syndrome share some common biological patterns, but each one experiences these uniquely. Functional medicine helps identify which systems need the most support for that individual child.

⚡Mitochondria
These are the cell’s energy factories. In Down syndrome, mitochondrial enzymes can function less efficiently because of oxidative stress, B vitamin deficiencies or expression of genes on chromosome 21. That can lead to low muscle tone, slow motor development, or fatigue. Nutrients like CoQ10, riboflavin (B2), thiamine (B1), and carnitine can help improve energy metabolism so cells can do their job.

⚛️Methylation
Methylation helps the body make neurotransmitters, detoxify, and repair DNA. Some children with Down syndrome have altered methylation patterns that can affect attention, language, and mood. Supporting this process with active folate (folinic acid), methyl B12, and P5P (active B6) can help optimize gene expression and neurochemical balance, though the right approach is unique for every child.

🦋Thyroid Function
Thyroid hormones guide growth, metabolism, and brain development. Hypothyroidism is common in Down syndrome, but many children also have poor conversion of T4 to active T3 or elevated reverse T3, issues that basic screening can miss. Assessing a full thyroid panel and ensuring nutrients like selenium and zinc are adequate helps improve hormone activation and energy regulation.

💩Gut Health
Constipation, dysbiosis, and low pancreatic enzymes are common in Down syndrome and can impact nutrient absorption, mood, and immunity. A sluggish gut may also recycle toxins and hormones, creating inflammation and discomfort. Supporting healthy digestion with probiotics, fiber, digestive enzymes, and gentle motility aids can make a remarkable difference in energy, attention, and overall comfort.

🛡️Immune Regulation
Children with Down syndrome often experience more frequent infections or autoimmune tendencies due to imbalanced immune signaling. This can stem from oxidative stress, gut imbalance, or chronic stealth microbes such as strep or mycoplasma. Addressing underlying inflammation, restoring gut balance, and supporting the immune system with nutrients like vitamin C, zinc, and NAC helps strengthen overall resilience.

☣️Oxidative Stress and Detoxification
Extra copies of genes like SOD1 and CBS on chromosome 21 can increase oxidative load, which can overwhelm detoxification and mitochondrial pathways. This may make some children more sensitive to environmental toxins or medications. Antioxidants such as glutathione, NAC, vitamin E, and alpha-lipoic acid can help rebalance redox status and support the body’s natural detoxification systems.

🥬Nutrient Status
Even with a balanced diet, gastrointestinal absorption issues can lead to nutrient deficiencies. Common deficiencies include zinc, B12, magnesium, vitamin D and iron. Using organic acid testing to evaluate functional markers of vitamin status combined with testing blood levels provides a clearer picture of how nutrients are being used in the body, helps identify the underlying cause of deficiency, and guides more precise supplementation.

😴Sleep and Nervous System Regulation
Sleep apnea, histamine intolerance, and iron or vitamin D deficiency can all affect rest and behavior in children with Down syndrome. Poor sleep disrupts growth hormone, mood, and learning. Evaluating airway health, histamine balance, calming neurotransmitter support and nutrient repletion can restore more restful sleep, which is essential for healing, cognition, and emotional regulation.

All of these areas can be measured and addressed through functional medicine. By using advanced lab testing, such as organic acid testing, stool analysis, and blood nutrient evaluation. We can see where the body needs extra support. This makes progress not just possible, but trackable and personalized for every child.

Every child with Down syndrome has their own pattern of strengths and challenges. Functional medicine doesn’t focus on what’s “wrong”. It looks at what’s possible when the body’s systems are supported to function at their best.

💙💛 Awareness is the first step. Action is where healing begins.

10/04/2025

October is Down Syndrome Awareness Month. We’ll be sharing information about Down syndrome all month long. 💛💙

Did you know?

Chromosome 21 contributes about 1.5 to 2 percent of the entire human genome. When an individual has an extra copy of this chromosome, as in Down syndrome, it results in a 50 percent increase in the presence of all the genes located on chromosome 21. Within this chromosome lies a particularly important segment known as the Down Syndrome Critical Region (DSCR), defined as 21q22.13 to 21q22.3. This region contains approximately 30 to 40 genes and represents about 37 percent of chromosome 21. Many of the genes most strongly associated with the physical and cognitive features of Down syndrome are believed to reside within this section. When scaled to the entire genome, the DSCR accounts for roughly 0.56 to 0.74 percent.

While this small percentage has far-reaching implications for health and development, it’s not the whole story.

Here’s the bigger picture: the other 99.3% of the genetics of a child with Down syndrome also plays an enormous role in how they present. Countless single nucleotide polymorphisms (SNPs) across the rest of the genome influence neurotransmitters, methylation, detoxification, immune regulation, mitochondrial function, and many other aspects of health and development. SNPs are small variations in DNA, single “letter” changes, that can alter how efficiently a gene works, sometimes subtly and sometimes in ways that significantly impact health. This is why individuals with Down syndrome are so different from one another, just like anyone else. Their unique genetic background shapes their strengths, their challenges, and their health outcomes.

This is why two children with the same diagnosis can look, learn, and thrive in completely different ways. Understanding both the impact of chromosome 21 and the contribution of the rest of the genome is key to supporting each child as an individual, not just as a diagnosis. 💙

10/02/2025

🌟 Down Syndrome Awareness Month 🌟

This month is about more than awareness. It’s about honoring each child and adult with Down syndrome as a whole person, not a diagnosis.

At the Peirson Center, we work every day to optimize the health of children with Down syndrome so they can thrive and rise above the outdated myths and misconceptions. That means looking at their individual medical needs; supporting digestion, metabolism, immune health, cognition, and more; not just following assumptions based on an extra chromosome.

Every child deserves to be respected as the unique person they are, with their own strengths, challenges, and potential. When we support their health in a personalized way, we give them the best opportunity to shine.

💙💛 Let’s use this month to celebrate their individuality and commit to a future where children with Down syndrome are seen, supported, and respected for exactly who they are.