Orofacial abnormalities in mucopolysaccharidosis and mucolipidosis type II and III:A systematic review

Mucopolysaccharidoses (MPSs) and mucolipidosis II and III (ML II and III) often manifest with orofacial (progressive) abnormalities, which may have a major impact on quality of life. However, because these patients have multiple somatic health issues, orofacial problems are easily overlooked in clinical practice and available literature on this topic solely consists of case reports, small case series, and small cohort studies. The aim of this systematic review was to gain more insight in the nature and extent of orofacial abnormalities in MPS, ML II, and III. A systematic review of all previously published articles addressing orofacial abnormalities in MPS, ML II, and III was performed. Both clinical studies and case reports were included. Outcome was the described orofacial abnormalities, subdivided into abnormalities of the face, maxilla, mandible, soft tissues, teeth, and occlusion. The search resulted in 57 articles, describing orofacial features in 340 patients. Orofacial abnormalities were present in all subtypes of MPS, ML II, and III, and consisted of thickened lips, a hypoplastic midface, a high‐arched palate, hypoplastic condyles, coronoid hyperplasia, macroglossia, gingival hyperplasia, thick dental follicles, dentigerous cysts, misshapen teeth, enamel defects, and open bite. Orofacial abnormalities are present in all subtypes of MPS, ML II, and III. As orofacial abnormalities may cause complaints, evaluation of orofacial health should be part of routine clinical care

Mucolipidosis type II and type III: a systematic review of 843 published cases

Purpose: Mucolipidosis (ML) II, MLIII alpha/beta, and MLIII gamma are rare autosomal recessive lysosomal storage disorders. Data on the natural course of the diseases are scarce. These data are important for counseling, therapies development, and improvement of outcome. The aim of this study is to gain knowledge on the natural history of ML by obtaining data on survival, symptom onset, presenting symptoms, diagnosis, and pathogenic variants associated with the MLII or MLIII phenotype. Methods: A systematic review on all published MLII and MLIII cases between 1968 and August 2019 was performed. Results: Three hundred one articles provided data on 843 patients. Median age at diagnosis: 0.7 for MLII and 9.0 years for MLIII. Median survival: 5.0 for MLII and 62.0 years for MLIIIII. Median age of death: 1.8 for MLII and 33.0 years for MLIII. Most frequent causes of death in all ML were pulmonary and/or cardiac complications. Pathogenic variants were described in 388 patients (GNPTAB: 571, GNPTG 179). Conclusion: This review provides unique insights into the natural history of MLII and MLIII, with a clear genotype–phenotype correlation with the most frequent pathogenic variant c.3503_3504del in MLII and in MLIII alpha/beta c.22A>G for GNPTAB. All pathogenic GNPTG variants resulted in MLIII gamma