Phenotypic and genetic characterization of a family carrying two Xq21.1-21.3 interstitial deletions associated with syndromic hearing loss.

BACKGROUND: Sensorineural hearing impairment is a common pathological manifestation in patients affected by X-linked intellectual disability. A few cases of interstitial deletions at Xq21 with several different phenotypic characteristics have been described, but to date, a complete molecular characterization of the deletions harboring disease-causing genes is still missing. Thus, the aim of this study is to realize a detailed clinical and molecular analysis of a family affected by syndromic X-linked hearing loss with intellectual disability. RESULTS: Clinical analyses revealed a very complex phenotype that included inner ear malformations, vestibular problems, choroideremia and hypotonia with a peculiar pattern of phenotypic variability. Genomic analysis revealed, for the first time, the presence of two close interstitial deletions in the Xq21.1-21.3, harboring 11 protein coding, 9 non-coding genes and 19 pseudogenes. Among these, 3 protein coding genes have already been associated with X-linked hearing loss, intellectual disability and choroideremia. CONCLUSIONS: In this study we highlighted the presence of peculiar genotypic and phenotypic details in a family affected by syndromic X-linked hearing loss with intellectual disability. We identified two, previously unreported, Xq21.1-21.3 interstitial deletions. The two rearrangements, containing several genes, segregate with the clinical features, suggesting their role in the pathogenicity. However, not all the observed phenotypic features can be clearly associated with the known genes thus, further study is necessary to determine regions involved.

Feasibility and effectiveness of a population-based newborn hearing screening in an economically deprived region of Italy.

AIM: To describe the effectiveness of a population-based newborn hearing screening program in an economically deprived region of southern Italy. METHODS: A screening protocol was proposed for all newborns of the Campania region, starting on January, 2007. For infants identified with hearing loss, information on degree and type of hearing loss and presence of risk factors was collected. RESULTS: The infants born in the 3-year study period were 182,188. Among them, 146,026 (80%) were tested with OAE. Sensorineural hearing loss ≥40dBnHL was established for 159 infants (1.1×1000). Among the NICU and WIN infants, the rate of hearing loss was respectively 9×1000 and 0.67×1000. Follow-up information was available for 111 children (70%), as 48 (30%) got care in other regions or health facilities. Most infants were fitted hearing aids by 1 month after diagnosis and 15 children (13.5%) received a cochlear implant at a mean age of 25 months (SD 10). CONCLUSIONS: Even in a setting of population poverty, a universal newborn screening program can deliver satisfactory outcomes. The coverage and the tracking system of the program need to be improved, as well as the cooperation between public and private health services.