Congenital sucrase–isomaltase deficiency in Türkiye; a single center experience

Abstract

Background

Congenital sucrase–isomaltase deficiency (CSID) is a rare inherited carbohydrate malabsorption disorder caused by sucrase–isomaltase (SI) gene variants. In CSID, an autosomal recessively inherited disease, symptoms can also be seen in individuals with heterozygous mutations.

Methods

The variant spectrum was evaluated retrospectively in individuals who presented with chronic diarrhea between 2014 and 2022 and had undergone genetic testing of the SI gene considering CSID due to diet-related complaints.

Results

Ten patients with chronic diarrhea were genetically evaluated with SI gene sequencing. In patients diagnosed with CSID and whose symptoms improved with enzyme replacement therapy, the genetic mutation zygosity was found to be heterozygous at a rate of 90%. In 10% of the patients, the mutation was homozygous. Limiting consuming sucrose and isomaltose foods reduced the patients’ complaints, but the symptoms did not disappear completely. With the initiation of sacrosidase enzyme replacement therapy, the patient’s complaints completely disappeared.

Conclusion

In CSID, defined as an autosomal recessive disease, clinical symptoms can also be seen in heterozygous cases previously described as carriers, and these patients also benefit from sacrosidase enzyme replacement therapy. In light of these findings, the autosomal recessive definition of CSID does not fully characterize the disease.

What is Known:

1. CSID is a rare inherited carbohydrate malabsorption disorder caused by sucrase–isomaltase gene variants.

2. In congenital sucrase–isomaltase deficiency, an autosomal recessively inherited disorder, symptoms can also be seen in individuals with heterozygous mutations.

What is new:

1. Severe disease symptoms can also be seen in heterozygous cases, which were thought to be carriers because the disease was previously described as autosomal recessive.

2. Sacrosidase enzyme replacement therapy also eliminates the disease symptoms in patients with heterozygous CSID mutations.

3. This is the second study on sucrase–isomaltase enzyme deficiency pediatric groups in Türkiye and Europe.

Impact statement

This is the study to evaluate the congenital sucrase-isomaltase enzyme deficiency in chronic diarrhea cases covering adults and childhood in our country and the clinical features and treatment response characteristics of the variants detected in these patients.

In addition, another aim of our study is that sucrase–isomaltase enzyme deficiency should be considered in the differential diagnosis and should be kept in mind, especially in cases with chronic diarrhea whose cause cannot be determined in childhood.

Keywords:

• Chronic diarrhea
• sucrase-isomaltase deficiency
• children
• malnutrition
• sucraid enzyme treatment
• congenital diarrhea

Acknowledgments

We thank his parent and child for their support in providing data.

Ethics approval and consent to participate

His parents or legal guardians of patients provided signed informed consent. This project was approved by the Ege University Clinical Research Ethics Committee on 24 March 2022, with the decision letter No. E-99166796-050 and decision No. 22-3.1 T/60. Our study was prepared in accordance with the ethical standards specified in the declaration of Helsinki and its subsequent amendments or similar ethical standards, and ethics committee approval is available.

Consent for publication

Not applicable.

Authors’ consent for publication

All authors approved publication permission.

Author contributions

All authors contributed to the study’s conception and design. All authors read and approved the final manuscript. DB, BK, EKT, MK and SA conceptualized and designed the study, drafted the initial manuscript, reviewed and revised the manuscript, final approval of the version to be published.

BG, YÇA, BA, AS, the data collection instruments, collected data, carried out the initial analyses, and reviewed and revised the manuscript, drafting the article or revising it critically for important intellectual content; and final approval of the version to be published.

FÇ, HO; conceptualized and designed the study, coordinated and supervised data collection, and critically reviewed the manuscript for important intellectual content, substantial contributions to conception and design, acquisition of data, or analysis and interpretation of data.

Disclosure statement

The authors declare that they have no conflict of interest.

Availability of data and materials

Not applicable.

Data availability statement

The data supporting this study’s findings are available from the corresponding author upon reasonable request.