Incidence of down syndrome: Hypotheses and reality

Down Syndrome Screening in India: Are We There Yet?

Down syndrome is the most common cause of intellectual disability among live born children and is amenable to prenatal detection. Screening for Down syndrome on a population basis requires a thorough understanding of the principles involved in the screening tests. We discuss the rationale behind the commonly available screening tests and the Indian scenario in this setting.

Enlarged vestibular aqueducts and other inner-ear abnormalities in patients with Down syndrome

BACKGROUND

Histopathological anomalies of inner-ear structures in individuals with Down syndrome have been well documented; however, few studies have examined the radiological features.

METHODS

A retrospective study was conducted of temporal bone computed tomography images in 38 individuals (75 ears) with Down syndrome to evaluate the prevalence of inner-ear abnormalities and assess vestibular aqueduct widths.

RESULTS

Inner-ear anomalies were identified in 20 of the 38 individuals (52.6 per cent). Seven of the 75 temporal bones (9.3 per cent) were found to have higher than previously reported. A dilated internal auditory canal and vestibule were more common among the present study group, while prior studies have demonstrated internal auditory canal stenosis and decreased vestibule size.

CONCLUSION

Down syndrome patients exhibit a high prevalence of dysplastic inner-ear features that confer substantial risk of sensorineural hearing loss. Computed tomography is a useful screening aid to detect inner-ear abnormalities, particularly enlarged vestibular aqueducts, which cause preventable sensorineural hearing loss in this population.