September 2019 HSC Section 1 Congenital and Pediatric Problems

B.J. Liming et al. / International Journal of Pediatric Otorhinolaryngology 90 (2016) 251 e 258

Table 1 Diagnostic considerations.

Consensus

Question

Agree

Partially agree

1.Which children should be offered comprehensive genetic testing?

! After an audiogram, comprehensive genetic testing has the highest diagnostic yield of any single test for bilateral sensorineural hearing loss [1,2] . ! Nonsyndromic children with unilateral hearing loss should not be offered genetic testing as part of initial workup. ! Comprehensive genetic testing should be offered to children with bilateral ANSD, or unilateral ANSD if imaging for cochlear nerve dysplasia is negative and no obvious acquired cause exists ! In the setting of comprehensive genetic testing, single gene testing is of low diagnostic yield and should not be offered as part of an initial workup unless a known family history exists. ! Directed genetic testing for GJB2/GJB6 should be considered if comprehensive genetic testing is unavailable. ! Directed genetic testing may be considered in consultation with a geneticist if comprehensive genetic testing is negative but suspicion for a genetic cause still exists. ! Temporal bone imaging is of low diagnostic yield when routinely employed in the setting of symmetric bilateral hearing loss. ! For unilateral, asymmetric or mixed loss, the diagnostic yield of imaging is higher and should be considered. ! Children who are cochlear implant candidates with profound hearing loss may bene fi t from CT or MRI to assess for cochlear dysplasias and cochlear nerve hypoplasia/ aplasia. ! The risks of ionizing radiation from CT must be balanced with the risks of the need for general anesthesia for MRI. ! MRI allows inclusion of a brain survey and is the better imaging modality for most peripheral auditory abnormalities. ! Temporal bone imaging with MRI is considered in children with bilateral ANSD and no obvious acquired cause and recommended in the setting of unilateral ANSD ! Temporal bone imaging should not be performed during the neonatal period unless indicated for other reasons (ie brain MRI). ! Given the 2 e 3 fold increased risk of ocular abnormalities in children with nonsyndromic SNHL, ophthalmology evaluation is warranted. ! Genetic testing may identify children who should have a cardiac workup. ! In a child with bilateral severe to profound HL and/or If there is a family history of childhood sudden death or a personal history of syncope or known cardiac arrhythmia an electrocardiogram should be ordered. ! Cardiology consult should not be ordered at the onset of diagnosis of hearing loss ! Congenital CMV causes 20 e 25% of all congenital sensorineural hearing loss [3] . ! CMV saliva/urine PCR or shell viral culture is highly speci fi c for congenital CMV in the fi rst three weeks of life should be performed when newborn hearing screen is failed. ! Blood spot PCR CMV testing can be used as an adjunct diagnostic test after the fi rst three weeks of life where available. It has high speci fi city but variable sensitivity. ! A positive test may guide treatment for CMV associated hearing loss. Treatment is currently only indicated for symptomatic CMV disease to improve hearing and neurodevelopmental outcomes [4] . Treatment with valganciclovir may improve hearing outcomes in children with congenital CMV infection in which hearing loss is the only symptom, but is not standard of care at this time. ! Comprehensive genetic testing is not universally available. ! A negative test does not rule out a genetic cause.

! 62%

! 38%

! 62%

! 23%

! 54%

! 46%

! 92%

! 100%

2. Should single gene or directed genetic testing be used?

! 54%

! 30%

! 77%

! 23%

! 92%

! 8%

3. Should temporal bone imaging be performed?

! 30%

! 46%

! 92%

! 8%

! 77%

! 23%

! 69%

! 15%

! 92%

! 8%

! 62%

! 23%

! 76%

! 8%

4. Should ophthalmology consult routinely be ordered? 5. Should a cardiac evaluation be routinely requested?

! 85%

! 15%

! 77% ! 85%

! 15% ! 15%

! 85% ! 85% ! 100%

! 15%

6. Should testing for CMV be considered?

! 8%

! 100%

! 100%

Section 4: Workup of child with sensorineural hearing loss

speci fi c in the fi rst 3 weeks of life. PCR based assays may be per- formed retrospectively on blood spots where available and have excellent speci fi city but variable sensitivity. After and audiogram and physical exam, comprehensive genetic testing (CGT) that relies on next generation sequencing (NGS) methodologies should guide subsequent workup in children with bilateral sensorineural hearing loss. The diagnostic rate is approxi- mately 40 e 65% but varies depending on the severity and symmetry of hearing loss and ethnicity [1,2] . Genetic testing should take into consideration the goals of the family and pre-testing counseling must appropriately address the diagnostic rates of comprehensive genetic testing and the fact that a negative genetic test does not rule out a genetic cause of hearing loss. A shared decision making model should be used when deciding to pursue genetic testing and genetic counselors have an important role in the genetic testing process. The physical examination and presence of other risk factors will dictate additional workup needed in the child with negative genetic testing. Some authors here advocate CGT only if single gene testing

The workup of the child with sensorineural hearing loss is ul- timately guided by the history and physical examination, the audiologic phenotype and the patient's ethnicity. In the setting of unilateral hearing loss, genetic testing has a limited role unless syndromic hearing loss is suspected (ie branchio-oto-renal syn- drome, VACTERL, CHARGE, Waardenburg syndrome). Temporal bone imaging should be considered at the time of diagnosis of unilateral hearing loss as cochlear nerve dysplasia is found in 1/3 of cases and nearly half of patients have abnormalities on imaging [7] . Congenital CMV can manifest with hearing loss as the only symptom and is a signi fi cant contributor to congenital hearing loss. Congenital CMV may present variably, with severity ranging from mild to profound. It can be unilateral or bilateral and be stable or progressive. Vestibular dysfunction is also possible. Testing for congenital CMV is not currently standardize or universally applied. Serum, urine and saliva PCR and culture based assays are highly

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