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Participant 128

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Female, age 6 with carnitine deficiency, thyroid disease, episodes of brain disease (episodic encephalopathy), problems with coordination (ataxia), and low blood sugar (hypoglycemia)

Date of Report

May 20, 2019


When the participant was almost two years old, she became ill and experienced hallucinations (altered mental status), problems with coordination (ataxia), and crossed eyes (strabismus). She continued to have these episodes for about a year. When she was three years old, she was hospitalized during an episode and tests revealed metabolomic abnormalities (hypoglycemia, ketosis, metabolic acidosis, and low levels of free carnitine). She had undetectable levels of thyroid stimulating hormone (TSH) and thyroid-related antibodies were positive. She improved while taking steroids and most of her symptoms went away. However, she continued to have low carnitine levels. She is currently taking a carnitine supplement, which has improved her carnitine levels.

Her younger sister is now two years old and may have a similar condition. When she was born, her newborn screening test results were abnormal with borderline low carnitine and an abnormal acylcarnitine profile with low C3 and C16. She may also be showing some signs of gross motor delay and poor eye tracking.

Symptoms / Signs

Shared symptoms/signs:

  • Low levels of carnitine in blood (decreased plasma carnitine)
  • Crossed eye (strabismus)

Older sister only:

  • Thyroid disease (Hashimoto thyroiditis; strongly positive TPO, TGAB, and TSI antibodies)
  • Episodes of brain disease (episodic encephalopathy)
  • Problems with coordination (ataxia)
  • Low blood sugar (hypoglycemia)
  • Mild heart structure abnormality (dilated aortic root)
  • Mild weakness of left arm
  • Abnormality of foot reflex (upgoing left toe)
  • Tiredness (lethargy) when exposed to heat
  • Positive for 21-hydroxylase antibodies

Younger sister only:

  • High arched palate
  • Bladder abnormality (vesicoureteral reflux)
  • Puffiness in hands and feet (edema)
  • Low muscle tone (infantile muscular hypotonia, mildly low axial muscle tone)
  • Gross motor delay
Current Treatments
  • Carnitine supplements – low carnitine levels
  • Occupational therapy (younger sister only) – motor delay
  • Rituxan infusions – autoimmune encephalitis
  • Synthroid – Hashimoto thyroiditis
Prior Treatments
  • Monthly IVIG (older sister only) – autoimmune encephalitis
  • Steroids (older sister only) – autoimmune encephalitis
Considered treatments
Previously Considered Diagnoses
  • Chromosomal abnormalities
  • Grave’s disease
  • Hashitoxicosis
  • Metabolomic abnormalities
  • Mitochondrial disease
  • Steroid-responsive encephalitis associated with autoimmune thyroiditis
Other Photographs
Genetic Variants of Interest

If this participant sounds like you or someone you know, please contact us!


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