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PubMed This is a summary of 15 peer-reviewed journal articles Updated

Is SPCD Linked to Autism or Developmental Delays?

At a Glance

Systemic Primary Carnitine Deficiency (SPCD) does not cause autism. Confusion stems from a shared acronym with a communication disorder. While untreated metabolic crises can cause brain injury and developmental delays, daily L-carnitine treatment protects brain development.

In this answer

3 sections

01

The Confusion Around “SPCD” and Autism

02

How Metabolic Crises Affect Development

03

Protecting Your Child’s Brain Development

Systemic Primary Carnitine Deficiency (SPCD) is not directly linked to autism spectrum disorder (ASD) [1][2][3]. Furthermore, the genetic mutation that causes SPCD does not directly cause developmental delays [4][5]. However, if a child with SPCD experiences a severe metabolic crisis before being diagnosed or treated, the resulting brain injury can lead to secondary developmental delays or neurological issues [4][6][7].

The Confusion Around “SPCD” and Autism

If you have been researching SPCD online, you may have seen articles discussing a link between SPCD and autism. It is important to know that these articles are almost certainly referring to Social (Pragmatic) Communication Disorder, which shares the exact same acronym (SPCD) [8][9][10].

Systemic Primary Carnitine Deficiency is a metabolic disorder caused by mutations in the SLC22A5 gene [1][11]. Social (Pragmatic) Communication Disorder is a developmental condition that is often discussed alongside autism [10][9]. There is no established causal link between the metabolic disorder (Systemic Primary Carnitine Deficiency) and neurodevelopmental disorders like autism [4][5][12].

How Metabolic Crises Affect Development

While the genetic condition itself does not directly cause cognitive impairment, the complications of untreated SPCD can [4][6].

Carnitine helps the body turn fat into energy. When carnitine levels drop too low—especially during illness or periods of fasting (such as going too long without eating, or when an infant sleeps through the night)—the body cannot tap into its fat stores for backup energy. This can trigger a metabolic crisis, which may involve:

  • Hypoketotic hypoglycemia: Dangerously low blood sugar levels without the presence of ketones (an alternative energy source for the brain) [4][7].
  • Encephalopathy: Brain dysfunction or swelling due to a severe lack of energy [4][13].

If a child experiences severe or prolonged hypoketotic hypoglycemia or encephalopathy, their brain is temporarily starved of energy. This can result in permanent brain injury, which may then cause secondary developmental delays, cognitive impairments, or seizures [4][5][12].

Protecting Your Child’s Brain Development

The key to protecting a child’s neurological development is preventing metabolic crises from happening in the first place [14][15].

Thanks to newborn screening, most children with SPCD are diagnosed early, before they ever experience a metabolic crisis [14][11]. By taking daily L-carnitine supplementation, your child’s carnitine levels are restored, preventing these dangerous energy drops [14][15][11].

It is also critical to always follow your metabolic team’s sick-day emergency protocol when your child is ill (such as when experiencing vomiting, diarrhea, or a high fever). During these times, they may temporarily need alternative energy sources like intravenous (IV) dextrose to protect their brain and other vital organs [14][11]. When treated early and consistently, children with SPCD are protected against secondary neurological injuries and are expected to have normal cognitive development [14][11].

Common questions in this guide

Does Systemic Primary Carnitine Deficiency cause autism?
No, Systemic Primary Carnitine Deficiency is not directly linked to autism. Online confusion often happens because Social (Pragmatic) Communication Disorder shares the exact same acronym (SPCD) and is a condition related to autism.
Can SPCD cause developmental delays in my child?
The genetic mutation for SPCD does not directly cause cognitive impairment. However, if a child with untreated SPCD suffers a severe metabolic crisis that starves the brain of energy, they can experience secondary developmental delays or seizures.
What happens to the brain during a metabolic crisis?
During a metabolic crisis, a child may experience dangerously low blood sugar without alternative energy sources (hypoketotic hypoglycemia) and brain dysfunction or swelling (encephalopathy). This temporary lack of energy to the brain is a medical emergency.
How can I protect my child's brain development with SPCD?
You can protect your child's brain by preventing metabolic crises through daily L-carnitine supplementation. It is also critical to follow your metabolic team's sick-day emergency protocol when your child is ill or cannot keep food down.
When should I take my child to the ER to prevent a metabolic crisis?
You should immediately follow your metabolic team's specific emergency protocol. Typically, if your child is vomiting, has a high fever, or is refusing to eat, they may need to go to the emergency room to receive alternative energy sources like IV dextrose.

Questions to Ask Your Doctor

Curated prompts to bring to your next appointment.

  1. 1.How long is it safe for my child to go without eating before we risk a metabolic drop?
  2. 2.At what point during an illness (like a stomach bug) should we skip the clinic and go straight to the emergency room?
  3. 3.Are my child's current blood carnitine levels in the optimal range to protect their neurological development?
  4. 4.Could you provide me with an updated emergency protocol letter that I can hand to the staff during an ER visit?
  5. 5.Given my child's medical history before their diagnosis, should we be monitoring any specific developmental milestones more closely?

Questions For You

Tap a prompt to share your answer — we'll use it plus this page's context to start a tailored conversation.

Related questions

Does a Baby's Positive SPCD Screen Mean the Mother Has It?Can Diet Alone Treat Primary Carnitine Deficiency?Do I Need Treatment For SPCD If I Have No Symptoms?How Does SPCD Affect the Heart and Cause Arrhythmias?How Do You Stop Fishy Body Odor from L-Carnitine?Is Systemic Primary Carnitine Deficiency Hereditary?Is There a Cure for Systemic Primary Carnitine Deficiency?What Are Common SPCD Misdiagnoses?What Are the Fasting Guidelines for SPCD Patients?SPCD Pregnancy Risks: Is It Safe to Get Pregnant?Primary vs Secondary Carnitine Deficiency ExplainedWhat is the SPCD ER Protocol During an Illness?What is the Life Expectancy for Someone with SPCD?Where is Systemic Primary Carnitine Deficiency Most Common?How Often Do You Need Tests for SPCD?What Triggers Muscle Breakdown in Adults With SPCD?Which Doctors Treat Systemic Primary Carnitine Deficiency

References

References (15)
  1. 1

    Molecular investigation in Chinese patients with primary carnitine deficiency.

    Zhang Y, Li H, Liu J, et al.

    Molecular genetics & genomic medicine 2019; (7(9)):e901 doi:10.1002/mgg3.901.

    PMID: 31364285
  2. 2

    Molecular Autopsy Implicates Primary Carnitine Deficiency in Sudden Unexplained Death and Reversible Short QT Syndrome.

    Gélinas R, Leach E, Horvath G, Laksman Z

    The Canadian journal of cardiology 2019; (35(9)):1256.e1-1256.e2 doi:10.1016/j.cjca.2019.05.014.

    PMID: 31472821
  3. 3

    A Rare Treatable Cause of Cardiomyopathy: Primary Carnitine Deficiency.

    Basan H, Azak E, Çetin İİ, et al.

    Molecular syndromology 2024; (15(2)):156-160 doi:10.1159/000534932.

    PMID: 38585546
  4. 4

    Systemic primary carnitine deficiency with hypoglycemic encephalopathy.

    Jun JS, Lee EJ, Park HD, Kim HS

    Annals of pediatric endocrinology & metabolism 2016; (21(4)):226-229 doi:10.6065/apem.2016.21.4.226.

    PMID: 28164076
  5. 5

    Response to "Cefepime-Induced Encephalopathy: A Possible Additional Mechanism of Neurotoxicity".

    Li HT, Wu T, Lin WR, Lim SN

    Neurocritical care 2020; (32(2)):642 doi:10.1007/s12028-019-00909-y.

    PMID: 31939091
  6. 6

    A case of atypical systemic primary carnitine deficiency in Saudi Arabia.

    Alghamdi A, Almalki H, Shawli A, et al.

    Pediatric reports 2018; (10(2)):7705 doi:10.4081/pr.2018.7705.

    PMID: 30069296
  7. 7

    A novel pathogenic variant in the carnitine transporter gene, SLC22A5, in association with metabolic carnitine deficiency and cardiomyopathy features.

    Jolfayi AG, Naderi N, Ghasemi S, et al.

    BMC cardiovascular disorders 2024; (24(1)):1 doi:10.1186/s12872-023-03676-z.

    PMID: 38166572
  8. 8

    Evaluating social (pragmatic) communication disorder.

    Mandy W, Wang A, Lee I, Skuse D

    Journal of child psychology and psychiatry, and allied disciplines 2017; (58(10)):1166-1175 doi:10.1111/jcpp.12785.

    PMID: 28741680
  9. 9

    Social (pragmatic) communication disorders and autism spectrum disorder.

    Baird G, Norbury CF

    Archives of disease in childhood 2016; (101(8)):745-51 doi:10.1136/archdischild-2014-306944.

    PMID: 26699538
  10. 10

    The comprehension of grammaticalized implicit meanings in SPCD and ASD children: A comparative study.

    Svindt V, Surányi B

    International journal of language & communication disorders 2021; (56(6)):1147-1164 doi:10.1111/1460-6984.12657.

    PMID: 34453388
  11. 11

    Primary carnitine deficiency - diagnosis after heart transplantation: better late than never!

    Grünert SC, Tucci S, Schumann A, et al.

    Orphanet journal of rare diseases 2020; (15(1)):87 doi:10.1186/s13023-020-01371-2.

    PMID: 32276632
  12. 12

    A newborn with seizures born to a mother diagnosed with primary carnitine deficiency.

    Chen S, Hu Y, Huang Y, et al.

    BMC pediatrics 2019; (19(1)):79 doi:10.1186/s12887-019-1452-4.

    PMID: 30885166
  13. 13

    A Rare Case Report of Hypoketotic Hypoglycemia Induced Seizures Due to Secondary Carnitine Deficiency in a 44-year-old Female.

    Bangolo A, Tesoro N, Onyeka S, et al.

    Journal of community hospital internal medicine perspectives 2024; (14(3)):68-71 doi:10.55729/2000-9666.1279.

    PMID: 39036584
  14. 14

    Clinical, biochemical, and molecular genetic characteristics of patients with primary carnitine deficiency identified by newborn screening in Shanghai, China.

    Chang S, Yang Y, Xu F, et al.

    Frontiers in genetics 2022; (13()):1062715 doi:10.3389/fgene.2022.1062715.

    PMID: 36568374
  15. 15

    Systemic primary carnitine deficiency induces severe arrhythmia due to shortening of QT interval.

    Lodewyckx P, Issa J, Gaschignard M, et al.

    Molecular genetics and metabolism 2023; (140(4)):107733 doi:10.1016/j.ymgme.2023.107733.

    PMID: 37979236

This page provides information on SPCD and developmental outcomes for educational purposes only. Always consult your child's metabolic team or pediatrician regarding their specific medical risks and emergency protocols.

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