Before Diagnosing Superior Mesenteric Artery (Wilkies) Syndrome in MELAS, other causes of Gastroparesis must be ruled out

We read with interest the article by Horna et al. about a 22-year-old male with mitochondrial encephalopathy, lactic acidosis, and stroke-like episode (MELAS) syndrome clinically presenting with stroke-like episodes, epilepsy, pancreatitis, perimyocarditis, gastroparesis, vomiting, constipation, and superior mesenteric artery syndrome (SMAS) [1] .SMAS was managed conservatively, which had a beneficial effect, so that the patient regained weight through feeding via home parenteral nutrition (HPN) [1] .The study is impressive, but some points require further discussion.The first point is that the underlying mutation responsible for MELAS has not been reported [1] .We should know whether MELAS in the index patient was due to an mtDNA defect or a mutation in a nuclear mitochondrial gene.Since >90% of MELAS cases are due to mtDNA mutations and 80% of patients carry the m.3243A>G variant, it is very likely that MELAS in the index patient was also due to the m.3243A>G variant.When an mtDNA defect is suspected, it is important to report the heteroplasmy rate of the causative variant in order to assess the genotype-phenotype correlation.The second point is that no family history was provided.To assess whether MELAS syndrome was inherited or occurred sporadically, it is important to know whether other first-degree relatives, especially the mother, were also affected and whether any of the affected relatives carried the same mutation as the index patient.The third point is that gastroparesis could also be due to autonomic denervation or smooth muscle myopathy.How was parasympathetic under-innervation ruled out?Did the patient undergo biopsy of the gastric smooth muscle to determine whether smooth muscle myopathy was present or not?What were the results of intestinal biopsy?Did the patient undergo a 13