Introduction
Nager syndrome is a type of acrofacial dysostosis. Ninety per cent of patients suffer conductive hearing loss of greater than 30 dBHL.Reference Herrmann, Karzon and Molter1 It is notoriously difficult to treat. Otological manifestations include congenital malformations of the pinnae and external auditory canals.Reference Opitz, Stoll, Ring and Nager2 Occlusion of the auditory canals renders hearing loss challenging to assess and treat in such patients. Patients with non-atretic auditory canals suffer from recurrent otitis media, requiring an average of two sets of tympanostomy tubes.Reference Herrmann, Karzon and Molter1
Nager syndrome may be caused by alterations in genetic dosage, regulation and expression.Reference Zhang, Dai, Liu and Ren3 This syndrome produces predominantly preaxial deformities, differentiating it from the mostly postaxial deformities seen in Miller syndrome.Reference Zhang, Dai, Liu and Ren3 Congenital craniofacial abnormalities include malar hypoplasia, micrognathia and cleft palate. In the upper limbs, the most common malformation is deformed or absent thumbs.4 Clinodactyly, syndactyly and arm-shortening (due to an absent radius) have also been observed in affected children. Mid-face and mandibular hypoplasias predispose patients to airway obstruction. Less commonly, cardiac, renal and urogenital abnormalities have also been observed.
This report presents a case of Nager syndrome in a three-year-old boy living in the north-east of England. To our knowledge, this is the first report of Nager syndrome associated hearing loss being treated with bone-anchored hearing aids (BAHAs).
Case report
A three-year-old, Caucasian boy was referred to a tertiary referral centre. His birth had been normal, with no pre-, peri- or post-natal difficulties. However, from birth the patient had been noted to have bilateral external auditory canal atresia and rudimentary pinnae (Figure 1). The extent of these malformations had made newborn otoacoustic emission screening impossible. Therefore, the patient had undergone visual reinforcement audiology, which revealed he suffered from bilateral, moderate conductive hearing loss. The patient had responded to frequencies of 500–4000 Hz at 20 dBHL via bone conduction, and at 60–70 dBHL unaided.
Fig. 1 Clinical photograph of a three-year-old boy with Nager syndrome, showing this patient's craniofacial abnormalities, tracheostomy and malformed pinna, and also his bone-anchored hearing aid. Published with the permission of the patient's mother.
The patient had faced multiple medical challenges early in life. He had been born with a misshapen cranium, right radial hypoplasia and an absent left thumb. He had required surgical repair of an atrioventricular septal defect and cleft palate. The patient had also required a tracheostomy and a percutaneous endoscopic gastrostomy for feeding. His mobility had initially been poor, requiring a specialist chair; with intense physiotherapy, his mobility had improved slightly. He had made modest progress with oral feeding, as well as with his speaking valve. In early 2010, the patient had been diagnosed with a left hydrocoele.
The patient's speech and language development had been severely attenuated by a combination of airway atresia and conductive hearing loss. Initially, his speech had been slow, and he had been unable to communicate effectively with his mother. However, by early 2010 he was able to speak two- to three-word sentences, and appeared at ease using communicative signs.
In mid-2010, aged three years eight months, the patient's conductive hearing loss was surgically treated. His cranial thickness was slightly below normal, at 3 mm or less. A 3 mm drill was used to attach titanium implants and abutments bilaterally. The surgical implant was placed inferiorly to the normal position used in adults; this ensured that the abutments were sited in bone of sufficient depth.
Three months after surgery, the patient had experienced no adverse effects, and was fitted with bilateral BAHA processors. He then experienced a significant improvement in communication ability, and tolerated his bilateral BAHAs exceptionally well.
After a further three months, the patient was making encouraging progress. His mother was exceptionally pleased and reported a remarkable improvement in his ability to communicate. The BAHAs continued to be well tolerated, with no adverse effects, and his speech was fairly clear during the clinic appointment.
Discussion
To our best knowledge, this is the first reported case of BAHAs being used to treat Nager syndrome associated hearing loss.
Bone-anchored hearing aids have proved to be an effective solution to conductive hearing loss. Furthermore, BAHAs have been shown to be an efficacious treatment for children with congenital hearing loss.Reference Powell, Burrell, Cooper and Proops5 We are aware of at least two children with Nager syndrome who have previously been treated with BAHAs.6, 7 However, until now there have been no formally reported cases in the literature.
• Bone-anchored hearing aids (BAHAs) are an effective treatment for conductive hearing loss
• The first report of Nager syndrome associated conductive hearing loss treated with BAHAs is presented
• In this patient, with acrofacial dysostosis, BAHA use was safe and effective
• The indications for BAHAs are expanding; BAHAs may be under-utilised
The use of BAHAs in children under the age of three or four years has previously been considered unsuitable, and implantation in young children has been associated with adverse outcomes.Reference Snik, Leijendeckers, Hol, Mylanus and Cremers8, Reference Lloyd, Almeyda, Sirimanna, Albert and Bailey9
Our patient with Nager syndrome, aged three years and eight months, was successfully treated with bilateral BAHAs for his conductive hearing loss. In recent years, the indications for the use of BAHAs have become more numerous.Reference Lloyd, Almeyda, Sirimanna, Albert and Bailey9 The presented case suggests that the indications for BAHA use can be expanded further still. This case also emphasises the potential benefits of surgery in patients with acrofacial dysostosis, suggesting that craniofacial surgery may be under-utilised in such patients.
Published observations indicate that sensorineural deafness is also possible in Nager syndrome patients.Reference Herrmann, Karzon and Molter1 In light of the resoundingly successful treatment of our patient's conductive hearing loss, there is cause for optimism in future treatment of Nager syndrome.
Bone-anchored hearing aids are a safe and effective method of treating hearing loss in patients with Nager syndrome. The excellent clinical response of the presented patient suggests that BAHAs could be used more frequently in the treatment of Nager syndrome in young children. This case also suggests that BAHAs may be generally under-utilised in the treatment of young children.
