A clinical case involving a 3-year-old boy who has shown signs of developmental delays since he was a baby

Let’s Discuss This Case

Rabia Akram
4 min readNov 14, 2023
Photo by Johnny Cohen on Unsplash

This information is fictional and intended for educational use.

This is my #case_scenarios_series#1

A 3-year-old boy presents with developmental delays evident since infancy. Parents note delayed milestones, such as speech and motor skills. Initial assessments reveal hypotonia and global developmental delays.

When he was 2 months old, he had his first tonic seizure.

What are Tonic seizures?

Tonic seizures are a type of epileptic seizure characterized by sudden, stiffening muscle contractions.

During a tonic seizure, a child may experience a sudden onset of muscle stiffness, typically in the arms, legs, or trunk.

These seizures can last for several seconds to minutes and may cause the child to fall if standing.

Tonic seizures are a part of generalized seizures and can be associated with various epilepsy syndromes.

At 4 months, he struggled to lift his head for more than a few seconds, and after 6 months, his muscle tone weakened progressively, along with ongoing developmental delays.

Muscle tone weekend?

In the context of the provided information, “muscle tone weakened progressively” refers to a gradual loss of normal muscle tension or firmness.

Typically, infants develop muscle tone as part of their motor skills development. However, in this case, the observed weakening of muscle tone means that the 4-month-old struggled to maintain the expected level of muscle firmness, and by 6 months, this weakness continued to progress.

Reduced muscle tone can impact various aspects of motor development, including the ability to lift the head, sit, and achieve other developmental milestones.

It could be indicative of an underlying issue affecting the neuromuscular system or development.

Further medical evaluation would be necessary to determine the specific cause of the observed muscle tone weakness and developmental delays.

Over the past year, he has had recurrent seizures characterized by gaze deviation and uncontrolled limb movements.

What are Recurrent Seizures?

It is a neurological condition characterized by repeated, unprovoked seizures.

Seizures occur due to abnormal electrical activity in the brain, leading to a wide range of symptoms, such as convulsions, loss of consciousness, or altered awareness.

Additionally, he has laryngomalacia, a condition causing noisy breathing due to softening of the larynx.

Despite being born healthy at full term, he’s now in the 3rd percentile for growth.

There is no family history of neurological disorders.

What is 3rd Percentile for Growth?

When a child’s measurements, such as height or weight, fall at the 3rd percentile, it means that they are smaller or lighter than 97% of children in the reference population.

This can be an indicator of slower growth or potential growth-related concerns.

Physical Examination

Physical examination reveals overall muscle weakness, but no distinct facial features.

Lab Tests

Lab tests, including brain MRI, amino acid profile, acylcarnitine analysis, urine organic acid analysis, karyotyping, array CGH, and whole exome sequencing, have yielded no definitive diagnosis.

So much medical terminology here. Let me simplify the complex medical terms into simpler versions.

These tests are commonly used in the diagnostic process for mitochondrial disorders, which are a group of genetic conditions that affect the mitochondria, the energy-producing structures within our cells.

Mitochondrial disorders can be quite complex and challenging to diagnose.

Let’s explain how each test relates to this context:

Brain MRI (Magnetic Resonance Imaging)

Brain MRI can reveal changes in brain structure due to lack of energy production in affected areas.

Amino Acid Profile

Mitochondrial disorders can disrupt the metabolism of amino acids, so measuring their levels can provide insights into the body’s metabolic balance, potentially indicating a mitochondrial disorder.

Acylcarnitine Analysis

This test helps identify disruptions in fatty acid metabolism, which is closely linked to mitochondrial function.

Abnormal acylcarnitine levels may suggest a mitochondrial disorder.

Urine Organic Acid Analysis

Mitochondrial disorders can lead to the accumulation of specific organic acids.

This test can identify abnormal levels, pointing to a metabolic disorder associated with mitochondrial dysfunction.


While not directly related to mitochondrial disorders, karyotyping may be performed to rule out chromosomal abnormalities as a cause of symptoms, ensuring a more comprehensive evaluation.

Array CGH (Comparative Genomic Hybridization)

This test can detect chromosomal imbalances, which may occasionally contribute to mitochondrial disorders or mimic their symptoms. It is used to exclude such possibilities.

Whole Exome Sequencing

Mitochondrial disorders often have a genetic basis. Whole exome sequencing can identify genetic mutations in genes responsible for mitochondrial function.

It’s a powerful tool in identifying the genetic underpinnings of these disorders.

Mitochondrial disorders are known for their clinical and genetic heterogeneity, making diagnosis challenging.

What is the most likely underlying condition in this 3-year-old boy based on the clinical presentation?

Mitochondrial Disease

Mitochondrial disorders can present with a combination of developmental delays, seizures, muscle weakness (hypotonia), and growth issues. Since the patient has undergone extensive genetic testing with no results, mitochondrial disease could be a consideration.

Further testing, such as a muscle biopsy, may be necessary for confirmation.

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Rabia Akram

My writing revolves around topics of self improvement and mental health concerns. My love for nature shines through as I often discuss about trees and outdoors.