Rare Recessive Disorder Hints at Crucial Role for 'Non-Essential' Protein

October 16, 2013 | A team of researchers seeking to pinpoint the genetic cause of a rare disorder of brain growth have implicated deficiencies of the amino acid asparagine in the disease phenotype. Four children from unrelated families – two in Israel and two in Canada – exhibited a distinctive set of symptoms including abnormally small heads, seizures, and developmental delays. Sequencing revealed that all four children were homozygous for a vanishingly rare variant of the ASNS gene, which is involved in asparagine synthesis. Although asparagine had previously been considered one of the “non-essential” amino acids, this finding suggests that it may play a key role in normal brain growth and development. It also opens the possibility of asparagine supplements as a treatment option – especially if the recessive condition can be detected prenatally in the future. Neuron