Table 3. [Autosomal Recessive Lysosomal Storage Disorders to Consider in the Differential Diagnosis of ML II]. - GeneReviews®

Differential Diagnosis Disorder	Gene	Clinical Features of Differential Diagnosis Disorder
Severe mucopolysaccharidosis type I (MPS I; Hurler syndrome)	IDUA	Coarse features Slowed statural growth Clawed hands	MPS I is more prevalent, has more signs of storage on physical exam, & has less severe dysostosis multiplex on radiographs.
Type I (infantile) GM1 gangliosidosis	GLB1	Radiographic features of dysostosis multiplex are indistinguishable in ML II (in early infancy & childhood) & GM1-gangliosidosis type 1 (in neonates). ¹	More hepatomegaly
Infantile galactosialidosis (OMIM 256540)	CTSA	Growth restriction Skeletal dysplasia	Storage phenomena more pronounced Presents as nonimmune hydrops fetalis more often than ML II
Infantile sialidosis (formerly called sialidosis type II or mucolipidosis I) (OMIM 256550)	NEU1	Dysmorphic Coarse features	May present as nonimmune hydrops fetalis In infants: more chronic disorder w/moderate organomegaly, dysostosis multiplex that is milder than in ML II, ² & minimal limitation of joint mobility Growth & cognitive development much less impaired
Infantile free sialic acid storage disease	SLC17A5	Coarse features Significant DD	Less facial dysmorphism & much less dysostosis multiplex Severe DD

Differential Diagnosis Disorder

Gene

Clinical Features of Differential Diagnosis Disorder

Overlapping w/ML II

Distinguishing from ML II

Severe mucopolysaccharidosis type I (MPS I; Hurler syndrome)

IDUA

Coarse features
Slowed statural growth
Clawed hands

MPS I is more prevalent, has more signs of storage on physical exam, & has less severe dysostosis multiplex on radiographs.

Type I (infantile) GM1 gangliosidosis

GLB1

Radiographic features of dysostosis multiplex are indistinguishable in ML II (in early infancy & childhood) & GM1-gangliosidosis type 1 (in neonates). ¹

More hepatomegaly

Infantile galactosialidosis (OMIM 256540)

CTSA

Growth restriction
Skeletal dysplasia

Storage phenomena more pronounced
Presents as nonimmune hydrops fetalis more often than ML II

Infantile sialidosis (formerly called sialidosis type II or mucolipidosis I) (OMIM 256550)

NEU1

Dysmorphic
Coarse features

May present as nonimmune hydrops fetalis
In infants: more chronic disorder w/moderate organomegaly, dysostosis multiplex that is milder than in ML II, ² & minimal limitation of joint mobility
Growth & cognitive development much less impaired

Infantile free sialic acid storage disease

SLC17A5

Coarse features
Significant DD

Less facial dysmorphism & much less dysostosis multiplex
Severe DD

From: GNPTAB-Related Disorders

GeneReviews^® [Internet].

Adam MP, Feldman J, Mirzaa GM, et al., editors.

Seattle (WA): University of Washington, Seattle; 1993-2024.

GeneReviews® chapters are owned by the University of Washington. Permission is hereby granted to reproduce, distribute, and translate copies of content materials for noncommercial research purposes only, provided that (i) credit for source (http://www.genereviews.org/) and copyright (© 1993-2024 University of Washington) are included with each copy; (ii) a link to the original material is provided whenever the material is published elsewhere on the Web; and (iii) reproducers, distributors, and/or translators comply with the GeneReviews® Copyright Notice and Usage Disclaimer. No further modifications are allowed. For clarity, excerpts of GeneReviews chapters for use in lab reports and clinic notes are a permitted use.

For more information, see the GeneReviews® Copyright Notice and Usage Disclaimer.

For questions regarding permissions or whether a specified use is allowed, contact: ude.wu@tssamda.

NCBI Bookshelf. A service of the National Library of Medicine, National Institutes of Health.