# Best Practices for the Nutritional Management of Infantile-Onset Lysosomal Acid Lipase Deficiency: A Case-Based Discussion

## TL;DR

This paper discusses best practices for managing the rare genetic disorder infantile-onset LAL-D through nutrition and enzyme replacement therapy to improve survival and quality of life.

## Contribution

The paper provides updated, case-based guidance for optimal nutritional management of infantile-onset LAL-D.

## Key findings

- Combining enzyme replacement therapy with nutritional management improves growth, gut function, and liver health.
- Substrate reduction therapy is essential for reducing systemic inflammation and improving survival.
- A multidisciplinary team is necessary to manage the complex, multisystemic nature of LAL-D.

## Abstract

Infantile-onset lysosomal acid lipase deficiency (LAL-D) (Wolman disease, historically) is a rare inherited, rapidly progressive disorder caused by pathogenic variants in the LIPA gene, which encodes the enzyme LAL. LAL is essential for the metabolism of cholesteryl esters and triglycerides. LAL deficiency leads to the accumulation of cholesteryl esters and triglycerides within the lysosomes, macrophages, and parenchymal cells in most tissue types, including those in the liver, gastrointestinal tract, and lymph nodes but excluding the central nervous system. Infants with rapidly progressive LAL-D present with gastrointestinal disturbance, adrenomegaly with calcification, hepatosplenomegaly, growth failure due to malabsorption, and systemic inflammation. If untreated, rapidly progressive LAL-D typically leads to death within the first year of life. Treatment takes the two-pronged approach of sebelipase alfa, a human lysosomal acid lipase enzyme replacement therapy (ERT) that improves lipid metabolism, combined with nutritional management. Dietary substrate (lipid) reduction, known as substrate reduction therapy, is essential for optimal management in LAL-D. Following a nutritional plan and managing gastrointestinal disturbances together reduce systemic inflammation and improve growth, gut function, liver health, quality of life, and survival in patients with infantile-onset LAL-D. A multidisciplinary specialized team is necessary to manage the highly complex, multisystemic conditions in these patients. Nutritional management of LAL-D has evolved with increasing experience with the clinical management of ERT-treated infantile-onset LAL-D. A review of guidance for best practice nutritional management is needed. This narrative review aims to provide updated recommendations and guidance for the optimal nutritional management of infantile-onset LAL-D.