Lactobacillus lactis CKDB001 ameliorate progression of nonalcoholic fatty liver disease through of gut microbiome: addendum

According to our recent study (N.Y. LEE et al. Gut Microbes 2020; 11:882-99.)¹, we reported that Lactobacillus and Pediococcus ameliorate progression of nonalcoholic fatty liver disease through modulation of the gut microbiome. According on the analysis method (Previous: 16s rRNA sequencing and Recent: whole gene sequencing), the probiotics named Lactobacillus bulgaricus that we used in the experiment was identified as Lactobacillus delbrueckii subsp. bulgaricus through 16s rRNA sequencing analysis. Recently, we performed a clearer analysis with whole gene sequencing to proceed with the clinical trial, it was identified as Lactobacillus delbrueckii subsp. lactis by whole gene sequencing. Therefore, we inform that the subspecies have been changed to lactis through WGS. Read L. bulgaricus in the previous paper as L. lactis. In this addendum, the results of the change to L. lactis are summarized, and descriptions have been added to Materials & methods and Discussion.

Mis-splicing of the GALNS gene resulting from deep intronic mutations as a cause of Morquio a disease

Background

Mucopolysaccharidosis-IVA (Morquio A disease) is a lysosomal disorder in which the abnormal accumulation of keratan sulfate and chondroitin-6-sulfate is consequent to mutations in the galactosamine-6-sulfatase (GALNS) gene. Since standard DNA sequencing analysis fails to detect about 16% of GALNS mutant alleles, gross DNA rearrangement screening and uniparental disomy evaluation are required to complete the molecular diagnosis. Despite this, the second pathogenic GALNS allele generally remains unidentified in ~ 5% of Morquio-A disease patients.

Methods

In an attempt to bridge the residual gap between clinical and molecular diagnosis, we performed an mRNA-based evaluation of three Morquio-A disease patients in whom the second mutant GALNS allele had not been identified. We also performed sequence analysis of the entire GALNS gene in two patients.

Results

Different aberrant GALNS mRNA transcripts were characterized in each patient. Analysis of these transcripts then allowed the identification, in one patient, of a disease-causing deep intronic GALNS mutation. The aberrant mRNA products identified in the other two individuals resulted in partial exon loss. Despite sequencing the entire GALNS gene region in these patients, the identity of a single underlying pathological lesion could not be unequivocally determined. We postulate that a combination of multiple variants, acting in cis, may synergise in terms of their impact on the splicing machinery.

Conclusions

We have identified GALNS variants located within deep intronic regions that have the potential to impact splicing. These findings have prompted us to incorporate mRNA analysis into our diagnostic flow procedure for the molecular analysis of Morquio A disease.

Electronic supplementary material

The online version of this article (10.1186/s12881-018-0694-6) contains supplementary material, which is available to authorized users.