Child with Glutaric Aciduria Type 1

Summary

Dr. Rihanna Bahan discusses Glutaric Aciduria Type 1 (GA1), a rare genetic disorder affecting amino acid metabolism. Symptoms include seizures and neurodegenerative crises, often misdiagnosed as shaken baby syndrome. Early diagnosis through newborn screening and dietary management can prevent neurodegenerative diseases.

Takeaways

• 👩‍⚕️ Dr. Rihanna Bahan is a medical professional discussing Glutaric Aciduria Type 1 (GA1), a rare genetic disorder.
• 🔍 GA1 is characterized by a deficiency of the enzyme glutaryl-CoA dehydrogenase, which is crucial for breaking down certain amino acids.
• 📈 The worldwide prevalence of GA1 ranges from 1 in 30,000 to 1 in 110,000 live births, with a higher incidence in the Philippines at 1 in 95,000.
• 👶 Early symptoms of GA1 may include seizures, hypotonia, irritability, and dystonia, often presenting between 2 to 3 years of age.
• 🧬 GA1 is an autosomal recessive disorder, meaning it requires two copies of the mutated gene for the disease to manifest.
• 🚫 The absence of microcephaly (small head size) does not rule out GA1, as it's only present in 75% of patients.
• 🧬 Newborn screening can detect GA1 through the presence of specific metabolites, such as glutarylcarnitine and glutaric acid, in blood samples.
• 🏥 Misdiagnosis can occur, with symptoms sometimes being mistaken for shaken baby syndrome, a condition with different causes.
• 💊 Treatment for GA1 involves dietary restrictions to limit the intake of lysine and tryptophan, and carnitine supplementation to aid in toxin excretion.
• 🧠 Neurological complications of GA1 can include acute encephalopathic crises associated with infections or other stressors.
• 🌟 Early diagnosis and intervention are crucial for preventing neurodegenerative outcomes in GA1 patients.

Q & A

What is the topic of discussion in the presentation by Doctor Rihanna Bahan?

The topic of discussion is Glutaric Aciduria Type 1 (GA1), focusing on its diagnosis and management.

What is the significance of the case of Lily Cordis in the context of GA1?

Lily Cordis was initially misdiagnosed with shaken baby syndrome, but after hearing her story, doctors considered GA1. Her case highlights the importance of recognizing GA1 symptoms and the role of newborn screening in early detection.

When was Glutaric Aciduria Type 1 first described, and by whom?

Glutaric Aciduria Type 1 was first described in 1975 by Goodman and colleagues, who identified it in two siblings with a neurodegenerative disorder and increased glutaric acid in the urine.

How is Glutaric Aciduria Type 1 inherited?

Glutaric Aciduria Type 1 is inherited in an autosomal recessive manner.

What is the worldwide prevalence of Glutaric Aciduria Type 1, and what is the prevalence in the presenter's country?

The worldwide prevalence is reported as 1 in 30,000 to 1 in 110,000 live births. In the presenter's country, the prevalence is 1 in 95,000 live births.

What is the primary issue in Glutaric Aciduria Type 1?

The primary issue in GA1 is the lack of the enzyme glutaryl-CoA dehydrogenase, which is responsible for breaking down the amino acids lysine and tryptophan.

What are some of the neurological signs and symptoms associated with Glutaric Aciduria Type 1?

Neurological signs and symptoms associated with GA1 include hypotonia, irritability, jitteriness, dystonia, and in about 90% of patients, an acute encephalopathic crisis between 2 months to 3 years of age.

What is the role of newborn screening in the detection of Glutaric Aciduria Type 1?

Newborn screening plays a crucial role in detecting GA1 before symptoms emerge. It allows for early diagnosis and intervention, potentially preventing the development of neurodegenerative disease.

What are the metabolic products that accumulate in the body due to the deficiency of glutaryl-CoA dehydrogenase?

The metabolic products that accumulate in the body due to the deficiency of glutaryl-CoA dehydrogenase are glutaric acid and 3-hydroxyglutaric acid, which are toxic to the brain.

What is the significance of cranial imaging in patients with Glutaric Aciduria Type 1?

Cranial imaging in patients with GA1 often reveals temporal hypoplasia and widened CSF spaces, which account for the macrocephaly. It is also important in identifying the risk of acute subdural hematomas, which can be misdiagnosed as shaken baby syndrome.

What is the recommended dietary restriction for patients with Glutaric Aciduria Type 1?

The recommended dietary restriction for patients with GA1 includes limiting lysine and tryptophan intake by reducing natural protein and providing medical food to meet daily caloric needs. Carnitine supplementation is also used to enhance the secretion of toxins and replenish the coenzyme A used by the body.