Childhood Hearing Impairment in Senegal

Area of Science:

• Genetics
• Otolaryngology
• Public Health

Background:

• Hearing impairment (HI) is a significant global health concern, with limited etiological data in many African populations.
• Previous research in Senegal identified GJB2 variants in 34.1% of multiplex families with HI.
• Understanding the causes of childhood HI is crucial for early diagnosis and intervention.

Purpose of the Study:

• To determine the etiologies and clinical profiles of childhood hearing impairment in Senegal.
• To conduct a nationwide, community-based study on the causes of early-onset HI.
• To investigate the role of genetic and environmental factors in childhood HI in Senegal.

Main Methods:

• Nationwide recruitment of 406 participants from 295 families across 13 administrative regions.
• Clinical examination, audiological assessment (pure tone audiometry and/or auditory brainstem response).
• Pedigree analysis to infer inheritance patterns and consanguinity rates.

Main Results:

• Prelingual HI was prevalent (80%), with a mean age at diagnosis of 3.59 years.
• Sensorineural HI was the most common type (89.16%).
• Genetic factors were implicated in 52.7% of cases, environmental in 29.57%, with a high consanguinity rate (93%). Autosomal recessive inheritance was suggested in 61.2% of multiplex families.

Conclusions:

• Putative genetic factors, associated with high consanguinity, are the leading causes of early-onset HI in Senegal.
• The high consanguinity rate presents an opportunity to identify variants in known and novel genes responsible for childhood HI.
• This study provides critical etiological insights into childhood hearing impairment in Senegal, informing public health strategies.