Published online Sep 28, 2018. doi: 10.3748/wjg.v24.i36.4208
Peer-review started: June 22, 2018
First decision: July 31, 2018
Revised: August 2, 2018
Accepted: August 24, 2018
Article in press: August 24, 2018
Published online: September 28, 2018
Processing time: 95 Days and 20.7 Hours
A five-month old female infant presented with failure to thrive, developmental delay, jaundice, and dark urine.
Typical clinical findings and whole exome sequencing results led to a diagnosis of interstitial lung and liver disease (ILLD).
Genetic cause was suspected due to multiple system involvement, but a liver panel consisting of 41 genes related to liver diseases came back negative. Lysosomal storage disease was considered, but an enzyme panel for screening common lysosomal storage diseases was normal, as was the urine acidoglycoprotein level.
Laboratory findings were Cholestasis, anemia, abnormal blood coagulation profiled, thrombocytosis, and extreme leukocytosis. Whole exome sequencing revealed a novel truncating variant (c.2158C>T/p.Gln720Stop) and a novel tri-nucleotide insertion (c.893_894insTCG) in the methionyl-tRNA synthetase (MARS) gene.
X-ray, computed tomography scan, and ultrasound imaging revealed interstitial lung disease, hepatomegaly, kidney stones, and acetabular dysplasia.
Liver biopsy results showed severe hepatic steatosis, hepatic cells ballooning, lobular disarray, cholestasis, iron deposition, and mild fibrosis/lymphocyte infiltration/bile duct proliferation within the portal region.
Ursodeoxycholic acid, fat-soluble vitamins, antibiotics, oxygen therapy, and supportive treatment.
Previous reports of ILLD were associated with biallelic missense mutations in the MARS gene. Phenotypes, such as kidney stones, acetabular dysplasia, prolonged fever, and extreme leukocytosis have never been reported to be associated with ILLD.
ILLD is interstitial lung and liver disease caused by homozygous or compound heterozygous mutations in the MARS gene. Typical findings in ILLD include failure to thrive, developmental delay, interstitial lung disease, liver involvement (hepatomegaly, cholestasis, hepatic steatosis, fibrosis, and iron deposition), anemia, and thrombocytosis.
Regardless of race or ethnicity, ILLD should be considered in all patients with chronic liver diseases showing progressive interstitial lung involvement. Severe mutations may lead to more organ/system involvement and severe outcomes.