SNP Shot: Genomic Insights

Asparagine synthetase deficiency is a disorder that presents shortly after birth, leading to neurological issues. A common characteristic is microcephaly, an abnormally small head, which progressively worsens due to brain tissue atrophy. Individuals with this deficiency experience significant psychomotor delay, impacting both cognitive and physical development. They typically struggle with basic motor skills like sitting, crawling, and walking, and have difficulties with communication. In rare cases where developmental milestones are reached, regression often occurs.

Hyperreflexia (overactive reflexes) and hypotonia (low muscle tone) are frequently observed in those with asparagine synthetase deficiency. These muscle problems worsen over time, resulting in muscle stiffness, involuntary movements, and eventual spastic quadriplegia (paralysis of all four limbs). Epilepsy, or recurrent seizures, is also common, with varying seizure types. Tonic-clonic seizures (loss of consciousness, muscle rigidity, and convulsions), myoclonic seizures (muscle twitches), and tonic seizures (abnormal muscle contraction) are frequently seen. Individuals may also exhibit hyperekplexia, an exaggerated startle response. Cortical blindness, vision loss due to occipital cortex impairment, can occur in some cases.

Sadly, the life expectancy for individuals with asparagine synthetase deficiency is generally limited to childhood.

Inheritance:

Asparagine synthetase deficiency follows an autosomal recessive inheritance pattern. This means that for a person to be affected, they must inherit a mutated copy of the gene from each parent. The parents, while carrying one copy of the mutated gene, usually do not exhibit symptoms of the condition.