PMC

Hearing phenotype in distinct Stickler types. The percentages of hearing loss and its type for each type of Stickler syndrome (according to the affected gene) are shown in this figure. The group of hearing-impaired patients in which the type was not mentioned (6.4%), was proportionally divided among the three hearing loss groups.

Prevalences of hearing phenotype in Stickler patients, divided into age groups. The percentages of hearing loss and its type for each age group can be derived from this diagram. The group of hearing-impaired patients in which the type was not mentioned (6.4%), was proportionally divided among the three hearing loss groups.

The prevalence and type of hearing loss in Stickler syndrome. The percentages of the 313 included Stickler patients without and with hearing loss are displayed. Of the hearing-impaired patients, a subdivision into conductive, mixed and sensorineural hearing loss is provided. The group of hearing-impaired patients in which the type was not mentioned (6.4% of the total population), was proportionally divided among the three hearing loss groups.

PRISMA flow diagram, showing the overview of the search process. Schematic overview of the various steps involved in the search process, according to the PRISMA guidelines. We read 451 articles about Stickler syndrome, whose content, if relevant, could be included in the discussion. Data from 46 articles, meeting the inclusion criteria of the meta-analysis, are used to provide accurate prevalences about hearing loss in the results section of this article.

Typical audiograms for Stickler syndrome in general, and for STL3 and STL4. A) ARTA for Stickler patients in general (without genetic subclassification), based on the detailed audiometric results in 44 patients []. Mean air conduction thresholds of both ears are shown. B) ARTA for type III Stickler syndrome, based on the detailed audiometric results in 18 STL3 patients (52 different measurements) [,]. Air conduction thresholds of the best ear are shown, unless in patients where an air-bone gap was present, in which bone conduction of the best ear is shown. C) Average audiogram for type IV Stickler syndrome, based on the detailed audiometric results in 7 STL4 patients (median age 15y) [,]. Air conduction thresholds of the best ear are shown.