How is Salla disease inherited?

Salla disease follows an autosomal recessive inheritance pattern. This means a child must inherit a copy of the altered gene from both parents to develop the condition. Parents who each carry one copy typically do not show symptoms.

How rare is Salla disease?

Salla disease is classified as very rare. The estimated prevalence is approximately <1 in 1,000,000. Because rare disease data can be limited, actual numbers may differ from published estimates.

How is Salla disease diagnosed?

Information about diagnosis is currently limited for this condition.

Are there treatments for Salla disease?

Treatment for Salla disease is generally symptomatic and supportive. This means that care primarily focuses on managing the symptoms rather than curing the condition.

What complications can arise from Salla disease?

Salla disease can lead to various complications as it affects the nervous system. Over time, children may experience problems with muscle coordination and movement. Some may also face ongoing neurological challenges, which can impact their daily activities and overall quality of life.

How does Salla disease affect daily life for children?

Children with Salla disease may face challenges in daily life due to symptoms like poor muscle tone and coordination issues. Many may have developmental delays and may not reach certain milestones, such as walking. This can make everyday activities more difficult and may require additional support from caregivers.

What is the long-term prognosis for someone with Salla disease?

The long-term prognosis for individuals with Salla disease can vary, but the condition generally progresses gradually. While some children may achieve certain developmental milestones, many will continue to face neurological challenges and may experience a decline in function as they grow older. Information about long-term quality of life is limited due to the rarity of the disease.

What specific symptoms should families watch for in Salla disease?

Families should be aware of symptoms like hypotonia, which is poor muscle tone in infancy, and developmental delays. Other symptoms may include ataxia, muscle spasticity, and seizures. Involuntary slow movements of the limbs, known as athetosis, can also occur, and only about one-third of affected children learn to walk.

Kisho

Kisho is an information platform, not a medical provider. Nothing on this site constitutes medical advice, diagnosis, or treatment recommendations. All content is aggregated from publicly available sources (including ClinicalTrials.gov, PubMed, FDA.gov, and Orphanet) and is provided for informational purposes only. Clinical trial eligibility, treatment decisions, and any health-related actions should always be discussed with a qualified healthcare professional. Kisho does not endorse any specific therapy, organization, or clinical trial. Terms of use · Privacy policy

Salla disease - Clinical Profile, Genes & Research | Kisho | Kisho

Rare Disease

Salla disease

MONDO:0011449

Also known as:sialic acid storage diseaseSDsialuria, Finnish type

Find Clinical TrialsTrials

Overview

Salla disease is the mildest form of the free sialic acid storage disorders, which primarily affect the nervous system. Infants with Salla disease typically begin to experience poor muscle tone (hypotonia) during the first year of life,followed by slowly progressive neurological problems. Signs and symptoms include intellectual disability and developmental delay; seizures ; ataxia ; muscle spasticity; and involuntary slow movements of the limbs (athetosis). About one-third of affected children learn to walk. It is caused by mutations in the SLC17A5 gene and is inherited in an autosomal recessive manner. Treatment is generally symptomatic and supportive.

GeneticsAutosomal recessive · SLC17A5 (chr 6)

Clinical Trials1 registered · 1 recruiting

Clinical Presentation

Built from Human Phenotype Ontology (HPO) phenotype annotations and GeneReviews clinical descriptions. Features represent findings documented across known cases — not an exhaustive list of possible symptoms.

Features include: Delayed speech and language development, Inability to walk, Thickened calvaria, and Seizure and 13 more.

Organ System	Phenotype Count	Example Features
Brain and nerves	8	Delayed speech and language development, Inability to walk, Seizure

Genetic Landscape

Assembled from HGNC gene records, ClinGen gene-disease validity evidence, and ClinVar pathogenic variant data. Validity classifications reflect the strength of published evidence linking each gene to this disease.

SLC17A5 function has not been fully characterized.

Salla disease is associated with mutations in the SLC17A5 gene on chromosome 6.

GeneReviews

Clinical Guidance

Correlations between the type of SLC17A5 pathogenic variant and the severity of FSASD have been identified [, , , , , ]:

Diagnosis

Drawn from GeneReviews diagnostic guidelines, newborn screening panel status (RUSP), and ClinGen gene-disease validity classifications. Reflects current clinical evidence and consensus where available.

GeneReviews

Diagnostic Criteria

There are no consensus clinical diagnostic criteria for free sialic acid storage disorder (FSASD).

Suggestive Findings

FSASD should be suspected in individuals with the following clinical, imaging, and laboratory findings [, , , ].

Less Severe FSASD (including Salla disease)

Clinical findings

Truncal ataxia and hypotonia apparent at approximately age one year

Treatment

Compiled from FDA-approved drug records, orphan drug designations, and FDA Adverse Event Reporting System (FAERS) safety data. GeneReviews management guidance is included where available.

No approved treatments are currently available for Salla disease. The disease remains an area of unmet medical need.

GeneReviews

Management Guidelines

No clinical practice guidelines for free sialic acid storage disorder (FSASD) have been published. In the absence of published guidelines, the following recommendations are based on the authors' personal experience managing individuals with this disorder.

Evaluations Following Initial Diagnosis

To establish the extent of disease and needs in an individual diagnosed with FSASD, the evaluations summarized (if not performed as part of the evaluation that led to the diagnosis) are recommended.

Prognosis

Based on GeneReviews surveillance recommendations, HPO phenotype frequency and severity annotations, and published prevalence estimates from Orphanet and OMIM.

GeneReviews

Surveillance Guidelines

To monitor existing manifestations, the individual's response to supportive care, and the emergence of new manifestations, the evaluations summarized in are recommended. Table 6. Free Sialic Acid Storage Disorder: Recommended Surveillance

Research Landscape

Sourced from ClinicalTrials.gov and PubMed. Publication types are classified using NLM-curated article metadata; research type breakdowns reflect the nature of published work for this disease.

1 clinical trial registered, 1 recruiting. Interventions under study include other interventions. Research is primarily sponsored by academic and government institutions.

14 publications have been identified in PubMed for Salla disease. Research spans Basic Science / Preclinical (46%), Review / Meta-Analysis (15%), and Case Report / Case Series (15%).

Research Type	Count	% of Total
Laboratory research	6	46%

Data assembled from 8 of 12 sources · Last updated Sep 18, 2026, 7:24 PM UTC

MONDOHPOClinicalTrials.govFDAPubMedHGNCClinVarClinGenGeneReviewsOrphanetOMIMRUSP

Medical References

External Resources

OMIM

Online Mendelian Inheritance in Man

OMIM:604369

Orphanet

European rare disease database

Orphanet:309334

GARD

Genetic and Rare Diseases Info Center

GARD:4754

Questions for Your Care Team

→Should my partner and I meet with a genetic counselor to discuss carrier status and family planning?
→Are any of the 1 active clinical trial a good fit for my situation?
→Are there specialists or centers of excellence for this condition in my area?
→Is there a patient registry I should consider joining?

FAQ

Frequently Asked Questions

Common questions about Salla disease

Salla disease is a condition that primarily affects the nervous system. It is known as the mildest form of the group of disorders that involve the storage of free sialic acid. Children with this condition usually show signs of poor muscle tone during their first year of life and may later develop a variety of neurological issues. Over time, people with Salla disease can experience a range of symptoms including problems with muscle coordination and movement. The overall progression of the condition is gradual, and its presentation can vary among those affected.

Common symptoms include hypotonia (poor muscle tone) in infancy, developmental delay, intellectual disability, and seizures. Additional signs may include ataxia (lack of coordination), muscle spasticity, and involuntary slow movements of the limbs (athetosis). Only about one-third of affected children are able to learn to walk.

Salla disease is caused by mutations in the SLC17A5 gene. It is inherited in an autosomal recessive manner, meaning that a child needs to receive a copy of the mutated gene from both parents to develop the condition. Associated genes include SLC17A5.

← Back to All Diseases

GeneReviews

Differential Diagnosis

Biochemical Findings Increased urinary and cellular free sialic acid. The only disorders in which significantly elevated urinary and cellular free sialic acid is known to occur are sialuria (OMIM 269921), N-acetylneuraminate pyruvate lyase (NPL) deficiency, and free sialic acid storage disorder (FSASD) . Of note, in both sialuria and NPL deficiency, elevated free sialic acid is localized in the cytoplasm rather than the lysosome as in FSASD. The clinical course of sialuria involves developmental delay and hepatomegaly. NPL deficiency is associated with progressive cardiac myopathy and mild skeletal myopathy. Neither disorder is associated with the severe neurologic involvement that occurs in FSASD. Based on clinical suspicion and the finding of elevated free sialic acid in urine, one of two steps is taken to distinguish these conditions: • The cellular (cytoplasmic versus lysosomal) localization of free sialic acid can be documented; a predominantly lysosomal localization indicates FSASD. • Molecular genetic testing of SLC17A5 (for FSASD), GNE (for sialuria), or NPL (for NPL deficiency) can be performed. Note: Other causes of mild elevation in urinary free sialic acid may exist. Sialic acid bound to glycoproteins or glycolipids. If sialic acid bound to glycoproteins or glycolipids is stored, disorders such as sialidosis caused by sialidase (neuraminidase) deficiency (OMIM 256550) and galactosialidosis (OMIM 256540) caused by combined sialidase and galactosidase deficiency should be considered . These enzyme deficiencies involve lysosomal storage of sialic acid-containing glycoconjugates. Neuraminidase deficiency and galactosialidosis both have features typical of lysosomal storage diseases but vary widely in their manifestations. Clinical Findings See for other lysosomal storage disorders that are associated with the clinical manifestations of coarse facial features and developmental delays as well as other causes of nonimmune hydrops fetalis. Table 3. Other Genes of Interest in the Differential Diagnosis of Free Sialic Acid Storage Disorder

Clinical Finding(s) Overlapping w/FSASD	Gene	Disorder	MOI	Associated Enzyme
Aspartylglucosaminuria	AR	N(4)-(beta-N-acetylglucosaminyl)-L-asparaginase	—	—
ARSB	MPS VI (OMIM 253200)	AR	Arylsulfastase B	—
FUCA1	Fucosidosis (OMIM 230000)	AR	Tissue alpha-L-fucosidase	—

Source: GeneReviews — "Free Sialic Acid Storage Disorder"

Kisho

Salla disease

Overview

Clinical Presentation

Genetic Landscape

Clinical Guidance

Diagnosis

Diagnostic Criteria

Suggestive Findings

Treatment

Management Guidelines

Evaluations Following Initial Diagnosis

Prognosis

Surveillance Guidelines

Research Landscape

Medical References

External Resources

OMIM

Orphanet

GARD

Questions for Your Care Team

Questions for Your Care Team

FAQ

Frequently Asked Questions

Clinical Guidance

Explore clinical features

Penetrance

Differential Diagnosis

Neurologic

Developmental

Musculoskeletal

Feeding

Therapies Under Investigation

Clinical Trials

Recent Publications

Salla disease

Overview

Clinical Presentation

Genetic Landscape

Clinical Guidance

Diagnosis

Diagnostic Criteria

Suggestive Findings

Treatment

Management Guidelines

Evaluations Following Initial Diagnosis

Prognosis

Surveillance Guidelines

Research Landscape

Medical References

External Resources

OMIM

Orphanet

GARD

Related Diseases

Questions for Your Care Team

Questions for Your Care Team

FAQ

Frequently Asked Questions

What is Salla disease?

What are the symptoms of Salla disease?

What causes Salla disease?

How is Salla disease inherited?

How rare is Salla disease?

How is Salla disease diagnosed?

Are there treatments for Salla disease?

What complications can arise from Salla disease?

How does Salla disease affect daily life for children?

What is the long-term prognosis for someone with Salla disease?

What specific symptoms should families watch for in Salla disease?

Clinical Guidance

Explore clinical features

Penetrance

Differential Diagnosis

Neurologic

Developmental

Musculoskeletal

Feeding

Therapies Under Investigation

Clinical Trials

Recent Publications