Opitz trigonocephaly C syndrome associated with hearing loss

Compound heterozygous mutations in the IFT140 gene cause Opitz trigonocephaly C syndrome in a patient with typical features of a ciliopathy

〈 We report on an infant with Opitz trigonocephaly C syndrome (OTCS), who also had manifestations of ciliopathy, including short ribs (non-asphyxiating), trident acetabular roofs, postaxial polydactyly cone-shaped epiphyses, and dysplasia of the renal, hepatic and pancreatic tissues. To investigate the molecular cause, we used an exome sequencing strategy followed by Sanger sequencing. Two rare variants, both predicted to result in loss of functional protein, were identified in the IFT140 gene; a substitution at the splice donor site of exon 24 (c.723 + 1 G > T) and a 17 bp deletion, impacting the first coding exon (c.-11_6del). The variants were confirmed as being biallelic using Sanger sequencing, showing that the splice variant was inherited from the propositus mother and the deletion from the father. To date, Mainzer-Saldino syndrome, Jeune syndrome, and a form of nonsyndromic retinal dystrophy, have been identified as ciliopathies caused by IFT140 mutations. We provide the first description of an OTCS phenotype that appears to result from IFT140 mutations. The presentation of this patient is consistent with previous reports showing that OTCS already exhibited skeleletal and nonskeletal features of a ciliopathy.

Opitz trigonocephaly syndrome presenting with sudden unexplained death in the operating room: a case report

Introduction

Opitz trigonocephaly C syndrome (OTCS) is a rare malformation syndrome with the following features: synostosis of metopic suture, craniofacial abnormalities, severe mental retardation and a multitude of pathological findings affecting almost every organ system. OTCS is associated with a high mortality rate.

Case presentation

We describe the case of a Caucasian male baby who died at five months of age during surgical correction of the craniofacial anomaly.

Conclusion

As previously reported, OTCS may have an increased mortality rate during craniofacial surgery. Careful evaluation of surgery risk-benefit ratio is warranted in such patients.

Audiologic findings in Pfeiffer syndrome

Hearing loss has been described in patients with certain craniosynostotic syndromes but is poorly defined in Pfeiffer syndrome (PS). Our objective was to characterize the otologic and audiologic findings in PS. The records of PS patients evaluated at our craniofacial center over a 30-year period were culled. Only patients with a confirmed diagnosis and formal audiologic examination were included. Diagnostic criteria were characteristic mutations in fibroblast growth factor receptor 1 or 2 (FGFR1, FGFR2) or, in the absence of genetic testing, typical clinical findings of PS as determined by a clinical geneticist or the most senior author. Twenty patients met the inclusion criteria, and all had hearing loss. Twenty patients had traditional audiologic testing: 14 (70%) had pure conductive loss (minor to severe), and 3 (15%) had a mixed conductive/sensorineural loss (minor to severe). Two additional patients had hearing loss by Behavioral Observational Audiometry (sound fields method). One patient with early conductive hearing loss was subsequently determined to have a pure sensorineural deficit. Nine patients (45%) had permanent hearing loss significant enough to require audiologic amplification. All patients with PS demonstrated hearing loss, although the severity and the anatomic basis (ie., neural vs conductive) were variable. Conductive hearing loss, possibly caused by structural abnormalities, was most common. Sensorineural hearing loss was less common and may be related to the effect of FGFR mutations on cranial nerve and/or inner-ear development.