Theory-of-mind in individuals with Alström syndrome is related to executive functions, and verbal ability

Auditory Profile of Children With Some Rare Neurodevelopmental Disorders

Neurodevelopmental disorder is an umbrella term comprising many muscular, skeletal, metabolic, endocrinal, systemic, and immune-related diseases, which are caused due to the improper/inaccurate development of the central nervous system. Most of these disorders are highly prevalent, but some express rarely in human beings. Such disorders with least prevalence rates are known as rare neurodevelopmental disorders. The sensory system is affected in all individuals with these rare neurodevelopmental disorders, although to a varying extent. Sensory processing in terms of hearing loss is reported by many researchers in many rare neurodevelopmental disorders, but the pathophysiology of audiological findings are seldom investigated. In this chapter, the authors highlight the possible relationship between underlying cause and the resultant audiological symptoms in some of the rare neurodevelopmental disorders. Further, the research studies on the audiological profiling in such disorders are discussed.

Neurocognitive assessment and DNA sequencing expand the phenotype and genotype spectrum of Alström syndrome

Alström syndrome (OMIM#203800) is an ultra-rare autosomal recessive monogenic disease presenting pathogenic variants in ALMS1 (chromosome 2p13). It is characterized by early onset of blindness, hearing loss and systemic comorbidities, with delayed development without cognitive impairment. We aimed to investigate the cognitive functions and describe new pathogenic variants in Alström syndrome patients. Nineteen patients (13 adults, 6 children) underwent a thorough clinical, genetic, laboratory, instrumental, and neurocognitive assessment. Six new pathogenic variants in ALMS1 including the first described in exon 6 were identified. Four patients displayed a "mild phenotype" characterized by slow disease onset or absence of complications, including childhood obesity and association with at least one pathogenic variant in exon 5 or 6. At neurocognitive testing, a significant proportion of patients had deficits in three neurocognitive domains: similarities, phonological memory, and apraxia. In particular, 53% of patients showed difficulties in the auditory working memory test. We found ideomotor and buccofacial apraxia in 74% of patients. "Mild phenotype" patients performed better on auditory working memory and ideomotor apraxia test than "typical phenotype" ones (91.9 + 16.3% vs. 41.7 + 34.5% of correct answers, Z = 64.5, p < .01 and 92.5 + 9.6 vs. 61.7 + 26.3, Z = 61, p < .05, respectively). Deficits in auditory working memory, ideomotor, and buccofacial apraxia were found in these patients and fewer neuropsychological deficits were found in the "mild" phenotype group. Furthermore, in the "mild" phenotype group, it was found that all pathogenic variants are localized before exon 8.

Cochlear Implants in Alström Syndrome

OBJECTIVES

Too little is known about hearing loss rehabilitation in patients with Alström syndrome (AS). Benefits of hearing aids (HA) have not been fully documented and only one case treated with a Cochlear Implant (CI) has been described in the proceedings of a conference. Furthermore, comorbidities and risk of complications following surgical intervention may contraindicate Cochlear Implant procedures in these patients.The present case report concerns the first AS patient with CI in the literature.

METHODS

After reporting a concise description of the audiological profile of patients with AS described in the literature, the case of a 22-year-old woman with genetically confirmed Alström syndrome who underwent a sequential bilateral CI (Bi-CI) rehabilitation is reported. Audiological results before and after cochlear implantation are described.

RESULTS

The patient showed an excellent functional outcome with CIs, which enabled her to achieve communicative, social and academic results comparable with her peers, and no complications occurred.

CONCLUSIONS

AS is not necessarily an absolute contraindication to CI. For many AS patients, a good cognitive function and adequate life expectancy represent a clear indication to prompt and adequate hearing rehabilitation with CIs. The description of this type of clinical cases could in the future also generate indications for a tailored audiological treatment of patients with very specific needs, such as patients with Alström Syndrome.