Initial Therapeutic Approach with Pembrolizumab in Synchronous Multiple Cancers, Including Non-Small Cell Lung Cancer, Highly Positive for Programmed Death-Ligand 1 Expression.

Treatment of synchronous multiple primary cancers is clinically difficult. We report four cases of synchronous primary cancers, including advanced and metastatic non-small cell lung cancer (NSCLCs) highly positive for programmed death ligand-1 (PD-L1) expression and initially treated with pembrolizumab. Pembrolizumab was efficacious in 2 patients with NSCLC lesions, followed by chemoradiotherapy for esophageal cancer (case 1) and chemotherapy for gastric cancer (case 2). Both cancers in case 1 showed a complete response for 3 years, while progression of the accompanying gastric cancer resulted in mortality at 20 months in case 2. Both NSCLC and gastric cancer in case 3 failed to respond to pembrolizumab, but the accompanying laryngeal cancer in case 4 showed a complete response, and cytotoxic chemotherapy for NSCLC was continued for 18.0 months. Our clinical experience suggests that pembrolizumab is a useful therapeutic approach for patients with synchronous cancers, including NSCLC that highly expresses PD-L1.

Impact of Low Skeletal Muscle Mass on the Prognosis of Patients with Head and Neck Cancer Treated Nonsurgically.

INTRODUCTION: Sarcopenia, characterized by low skeletal muscle mass, and the outcome of cancer therapy are closely related based on recent research. This study aimed to evaluate the correlation between skeletal muscle mass and prognosis in head and neck cancer (HNC) patients. METHODS: In this study, 51 male patients with HNC treated nonsurgically between January 2016 and April 2018 at Shinshu University Hospital were evaluated. Skeletal muscle mass was assessed using bioelectrical impedance analysis, and the skeletal mass index (SMI) was calculated to classify the patients. RESULTS: The low-SMI group had a significantly worse overall survival (OS) than the normal-SMI group (3-year OS: 72.0% vs. 93.0%, p = 0.014), and there was a trend toward worse progression-free survival (PFS) in the low-SMI group (3-year PFS: 49.6% vs. 79.3%, p = 0.064). Multivariate analysis also showed that low SMI (p = 0.04) and severe N stage (p = 0.009) were significantly associated with poorer OS. CONCLUSION: The pretreatment assessment of SMI using bioelectrical impedance analysis is useful for identifying patients with poor prognoses. To improve the treatment outcome in HNC, we need to think of the intervention, such as cancer rehabilitation and nutritional support, during or before treatment, especially for patients with low SMI.

Detailed clinical features and genotype-phenotype correlation in an OTOF-related hearing loss cohort in Japan.

Mutations in the OTOF gene are a common cause of hereditary hearing loss and the main cause of auditory neuropathy spectrum disorder (ANSD). Although it is reported that most of the patients with OTOF mutations have stable, congenital or prelingual onset severe-to-profound hearing loss, some patients show atypical clinical phenotypes, and the genotype-phenotype correlation in patients with OTOF mutations is not yet fully understood. In this study, we aimed to reveal detailed clinical characteristics of OTOF-related hearing loss patients and the genotype-phenotype correlation. Detailed clinical information was available for 64 patients in our database who were diagnosed with OTOF-related hearing loss. As reported previously, most of the patients (90.6%) showed a "typical" phenotype; prelingual and severe-to-profound hearing loss. Forty-seven patients (73.4%) underwent cochlear implantation surgery and showed successful outcomes; approximately 85-90% of the patients showed a hearing level of 20-39 dB with cochlear implant and a Categories of Auditory Performance (CAP) scale level 6 or better. Although truncating mutations and p.Arg1939Gln were clearly related to severe phenotype, almost half of the patients with one or more non-truncating mutations showed mild-to-moderate hearing loss. Notably, patients with p.His513Arg, p.Ile1573Thr and p.Glu1910Lys showed "true" auditory neuropathy-like clinical characteristics. In this study, we have clarified genotype-phenotype correlation and efficacy of cochlear implantation for OTOF-related hearing loss patients in the biggest cohort studied to date. We believe that the clinical characteristics and genotype-phenotype correlation found in this study will support preoperative counseling and appropriate intervention for OTOF-related hearing loss patients.

Factors Affecting Nivolumab Therapy Outcome in Patients with Head and Neck Cancer: A Single-Center Analysis.

BACKGROUND: Nivolumab, a programmed death-1 antibody, is an immune checkpoint inhibitor approved in Japan in March 2017 for the treatment of recurrent or metastatic head and neck cancers (RM-HNCs) after platinum drug administration. This study aimed to evaluate the effectiveness and safety of nivolumab and to determine the prognostic factors affecting the treatment outcome, in a real-world setting in Japanese RM-HNCs. METHODS: Forty-six patients with RM-HNCs treated with nivolumab between April 2017 and April 2021 at Shinshu University Hospital were retrospectively assessed in this cohort study. RESULTS: The overall response rate was 17.4%, and the disease control rate was 41.3%. The median first and second progression-free survival (PFS1 and PFS2) were 2.6 and 10.3 months, respectively. The median overall survival (OS) was 14.8 months. Multivariate analysis showed that performance status (PS) (p = 0.003) and a decrease in neutrophil-lymphocyte ratio (NLR) (p = 0.02) were significantly associated with a better OS, and a decrease in NLR (p = 0.035) was associated with a better PFS2. CONCLUSIONS: This study is the first report of PFS2 in RM-HNCs treated with nivolumab; the long PFS2 may contribute to prolonged OS. We propose that the PS and a decrease in NLR could be useful clinical prognostic markers of nivolumab therapy, which can easily be evaluated in the clinical setting.

Non-ocular Stickler syndrome with a novel mutation in COL11A2 diagnosed by massively parallel sequencing in Japanese hearing loss patients.

OBJECTIVES: This study aims to document the clinical features of patients with COL11A2 mutations and to describe the usefulness of massively parallel sequencing. METHODS: One thousand one hundred twenty (1120) Japanese hearing loss patients from 53 ENT departments nationwide participated in this study. Massively parallel sequencing of 63 genes implicated in hearing loss was performed to identify the genetic causes in the Japanese hearing loss patients. RESULTS: A novel mutation in COL11A2 (c.3937_3948delCCCCCAGGGCCA) was detected in an affected family, and it was segregated in all hearing loss individuals. The clinical findings of this family were compatible with non-ocular Stickler syndrome. Orofacial features of mid-facial hypoplasia and slowly progressive mild to moderate hearing loss were also presented. Audiological examinations showed favorable auditory performance with hearing aid(s). CONCLUSION: This is the first case report of the genetic diagnosis of a non-ocular Stickler syndrome family in the Japanese population. We suggest that it is important to take both genetic analysis data and clinical symptoms into consideration to make an accurate diagnosis.

Gene expression profiles of the cochlea and vestibular endorgans: localization and function of genes causing deafness.

OBJECTIVES: We sought to elucidate the gene expression profiles of the causative genes as well as the localization of the encoded proteins involved in hereditary hearing loss. METHODS: Relevant articles (as of September 2014) were searched in PubMed databases, and the gene symbols of the genes reported to be associated with deafness were located on the Hereditary Hearing Loss Homepage using localization, expression, and distribution as keywords. RESULTS: Our review of the literature allowed us to systematize the gene expression profiles for genetic deafness in the inner ear, clarifying the unique functions and specific expression patterns of these genes in the cochlea and vestibular endorgans. CONCLUSIONS: The coordinated actions of various encoded molecules are essential for the normal development and maintenance of auditory and vestibular function.

Post-treatment Neutrophil/Lymphocyte Ratio Is a Prognostic Factor in Head and Neck Cancers Treated With Nivolumab.

Background/Aim: Inflammation and nutrition-based biomarkers, such as the neutrophil/lymphocyte ratio (NLR), platelet/lymphocyte ratio (PLR), lymphocyte/monocyte ratio (LMR), C-reactive protein/albumin ratio (CAR), prognostic nutritional index (PNI), systemic immune inflammation index (SII), and systemic inflammation response index (SIRI), have prognostic value for several types of malignancies. Markers that precisely reflect the prognosis of patients with head and neck cancers (HNCs) treated with immune-checkpoint inhibitors remain unclear. This retrospective study aimed to investigate the prognostic value of hematological markers before and after treatment with nivolumab in patients with recurrent or metastatic HNC (RM-HNC). Patients and Methods: We evaluated the clinical data of 44 patients with recurrent/metastatic head and neck squamous cell carcinoma treated with nivolumab between April 2017 and April 2023 at Shinshu University Hospital. Values of hematological biomarkers (NLR, LMR, PLR, CAR, PNI, SII, and SIRI) were calculated before and 4-6 weeks after nivolumab initiation. Receiver operating characteristic curves were constructed to determine the cutoff values of pre- and post-treatment markers for overall survival (OS) and progression-free survival (PFS). Results: Among all pre- and post-treatment markers, post-treatment NLR showed the highest area under the curve (AUC=0.702). A high post-treatment NLR (cutoff value, 4.01) was associated with a poor OS (p=0.027) and a tendency for shorter PFS (p=0.117). Multivariate analysis showed that a high post-treatment NLR was significantly associated with poor OS (p=0.026). Conclusion: A high post-treatment NLR was associated with poor response to nivolumab in head and neck cancers.

OTOF mutation screening in Japanese severe to profound recessive hearing loss patients.

BACKGROUND: Auditory neuropathy spectrum disorder (ANSD) is a unique form of hearing loss that involves absence or severe abnormality of auditory brainstem response (ABR), but also the presence of otoacoustic emissions (OAEs). However, with age, the OAEs disappear, making it difficult to distinguish this condition from other nonsyndromic hearing loss. Therefore, the frequency of ANSD may be underestimated. The aim of this study was to determine what portion of nonsyndromic hearing loss is caused by mutations of OTOF, the major responsible gene for nonsyndromic ANSD. METHODS: We screened 160 unrelated Japanese with severe to profound recessive nonsyndromic hearing loss (ARNSHL) without GJB2 or SLC26A4 mutations, and 192 controls with normal hearing. RESULTS: We identified five pathogenic OTOF mutations (p.D398E, p.Y474X, p.N727S, p.R1856Q and p.R1939Q) and six novel, possibly pathogenic variants (p.D450E, p.W717X, p.S1368X, p.R1583H, p.V1778I, and p.E1803A). CONCLUSIONS: The present study showed that OTOF mutations accounted for 3.2-7.3% of severe to profound ARNSHL patients in Japan. OTOF mutations are thus a frequent cause in the Japanese deafness population and mutation screening should be considered regardless of the presence/absence of OAEs.

A Spatial Transcriptome Reveals Changes in Tumor and Tumor Microenvironment in Oral Cancer with Acquired Resistance to Immunotherapy.

Although anti-programmed death-1 (PD-1) antibody therapy improves the prognosis in patients with head and neck squamous cell carcinoma (HNSCC), some patients exhibit disease progression even after showing a good response to the treatment initially because of acquired resistance. Here, we aimed to reveal the dynamic changes in the tumor and tumor microenvironment (TME) in a 77-year-old man diagnosed with oral squamous cell carcinoma who developed acquired resistance after the administration of nivolumab using spatial transcriptomics. The results showed that, before immunotherapy, the activated pathways in the tumor area were mainly related to the cancer immune system, including antigen processing cross-presentation, interferon-gamma signaling, and the innate immune system. After immunotherapy, the activated pathways were mainly related to epigenetic modification, including RMTs methylate histone arginine and HDAC deacetylates histones. Before immunotherapy, the activated pathways in the TME were mainly related to the metabolism of proteins, including SRP-dependent co-translational protein targeting the membrane. After immunotherapy, the activated pathways in the TME were related to sensory perception and signal transduction. Our study revealed that epigenetic-modification-related pathways were mainly activated after establishing acquired resistance, suggesting that epigenetic modification in the tumor may prevent cancer immune system activation via the anti-PD-1 antibody.

Prognostic significance of pre- and post-treatment hematological biomarkers in patients with head and neck cancer treated with chemoradiotherapy.

This study aimed to investigate the prognostic value of hematological biomarkers measured before and after treatment in patients with head and neck cancer (HNC). This study reviewed 124 patients with HNC who received chemoradiotherapy. Hematological biomarkers assessed before and after treatment were investigated. The pretreatment C-reactive protein/albumin ratio (pre-CAR) and post-treatment prognostic nutritional index (post-PNI) showed the highest area under the curve with cutoff values of 0.0945 and 34.9, respectively. Patients in the high pre-CAR group showed significantly worse prognosis than those in the low pre-CAR group with respect to the progression-free survival (PFS) (3-year PFS: 44.8% vs. 76.8%, p < 0.001) and overall survival (OS) (3-year OS: 65.8% vs. 94.0%, p < 0.001). Patients in the low post-PNI group showed significantly worse prognosis than those in the high post-PNI group with respect to the PFS (3-year PFS: 58.6% vs. 77.4%, p = 0.013) and OS (3-year OS: 75.2% vs. 96.9%, p = 0.019). Multivariate analysis revealed that advanced N stage (p = 0.008), high pre-CAR (p = 0.024), and low post-PNI (p = 0.034) were significantly associated with poorer OS. We suggest that the evaluation of hematological markers before and after treatment is useful for predicting disease progression and survival.

Perioperative management of a patient with a giant thyroglossal duct cyst: a case report.

Thyroglossal duct cysts (TGDC) are the most common type of congenital neck masses, which generally present in young adults. We present a rare case of a giant TGDC in a 77-year-old patient who required atypical perioperative management. The patient presented with a large soft mass on his anterior neck. Computed tomography showed a lobulated cystic mass measuring 18 × 16 cm, extending from the tongue base to the inferior level of the clavicle. Because difficult intubation was expected, the cyst was punctured and most of the fluid was drained prior to surgery. The swelling of the tongue base was remarkably reduced, and intubation was performed safely. The cyst was extracted using the Sistrunk procedure and tracheotomy was performed. Histopathological examination confirmed the diagnosis of TGDC. Preoperative volume reduction of the cyst and tracheotomy should be considered for oral intubation and postoperative airway management, respectively, in patients with large TGDC.

OTOF mutation analysis with massively parallel DNA sequencing in 2,265 Japanese sensorineural hearing loss patients.

The OTOF gene (Locus: DFNB9), encoding otoferlin, is reported to be one of the major causes of non-syndromic recessive sensorineural hearing loss, and is also reported to be the most common cause of non-syndromic recessive auditory neuropathy spectrum disorder (ANSD). In the present study, we performed OTOF mutation analysis using massively parallel DNA sequencing (MPS). The purpose of this study was to reveal the frequency and precise genetic and clinical background of OTOF-related hearing loss in a large hearing loss population. A total of 2,265 Japanese sensorineural hearing loss (SNHL) patients compatible with autosomal recessive inheritance (including sporadic cases) from 53 otorhinolaryngology departments nationwide participated in this study. The mutation analysis of 68 genes, including the OTOF gene, reported to cause non-syndromic hearing loss was performed using MPS. Thirty-nine out of the 2,265 patients (1.72%) carried homozygous or compound heterozygous mutations in the OTOF gene. It is assumed that the frequency of hearing loss associated with OTOF mutations is about 1.72% of autosomal recessive or sporadic SNHL cases. Hearing level information was available for 32 of 39 patients with biallelic OTOF mutations; 24 of them (75.0%) showed profound hearing loss, 7 (21.9%) showed severe hearing loss and 1 (3.1%) showed mild hearing loss. The hearing level of patients with biallelic OTOF mutations in this study was mostly severe to profound, which is consistent with the results of past reports. Eleven of the 39 patients with biallelic OTOF mutations had been diagnosed with ANSD. The genetic diagnosis of OTOF mutations has significant benefits in terms of clinical decision-making. Patients with OTOF mutations would be good candidates for cochlear implantation; therefore, the detection of OTOF mutations is quite beneficial for patients, especially for those with ANSD.

Bilateral delayed endolymphatic hydrops evaluated by bilateral intratympanic injection of gadodiamide with 3T-MRI.

The purpose of this study was to assess the diagnostic performance of 3T MRI after intratympanic injection of gadodiamide for delayed endolymphatic hydrops (DEH), and assess the relationship between endolymphatic hydrops (ELH) and vestibular function in patients diagnosed with DEH and confirmed by 3T MRI. Nineteen patients clinically diagnosed with DEH (11 ipsilateral DEH, 8 contralateral DEH) participated in this study. Diluted gadodiamide was administered to the bilateral tympanic cavity by injection through the tympanic membrane. At 24 hours post-injection, the ELH was evaluated by MRI. Patient vestibular functions were evaluated by caloric testing and cVEMP. ELH was observed in all patients (19/19: positive rate 100%). The distribution patterns of ELH varied between the cochlear or vestibular region. Vestibular ELH was observed in the affected ear in all ipsilateral DEH patients. In the contralateral DEH patients, however, there were individual differences in the distribution patterns of ELH. Six patients (1 ipsilateral DEH, 5 contralateral DEH) had bilateral ELH. No obvious relationships were observed between ELH and vestibular function. ELH distribution was complicated, particularly in the contralateral DEH cases. It was difficult to identify the existence of ELH by vestibular functional testing alone; therefore, 3T MRI is thought to be useful for identifying the affected ear. A significant number of cases had "bilateral" DEH, particularly among the contralateral DEH cases, indicating that we should pay careful attention to this pathology when treating DEH.

Comprehensive Genetic Analysis of Japanese Autosomal Dominant Sensorineural Hearing Loss Patients.

BACKGROUND: In general, autosomal dominant inherited hearing loss does not have a founder mutation, with the causative mutation different in each family. For this reason, there has been a strong need for efficient diagnosis methods for autosomal dominant sensorineural hearing loss (ADSNHL) patients. This study sought to verify the effectiveness of our analysis algorithm for the screening of ADSNHL patients as well as the usefulness of the massively parallel DNA sequencing (MPS). SUBJECTS AND METHODS: Seventy-five Japanese ADSNHL patients from 53 ENT departments nationwide participated in this study. We conducted genetic analysis of 75 ADSNHL patients using the Invader assay, TaqMan genotyping assay and MPS-based genetic screening. RESULTS: A total of 46 (61.3%) ADSNHL patients were found to have at least one candidate gene variant. CONCLUSION: We were able to achieve a high mutation detection rate through the combination of the Invader assay, TaqMan genotyping assay and MPS. MPS could be used to successfully identify mutations in rare deafness genes.

Detection and Confirmation of Deafness-Causing Copy Number Variations in the STRC Gene by Massively Parallel Sequencing and Comparative Genomic Hybridization.

OBJECTIVE: Copy number variations (CNVs), a major cause of genetic hearing loss, most frequently involve the STRC gene, located on chr15q15.3 and causally related to autosomal recessive non-syndromic hearing loss (ARNSHL) at the DFNB16 locus. The interpretation of STRC sequence data can be challenging due to the existence of a virtually identical pseudogene, pSTRC, that promotes complex genomic rearrangements in this genomic region. Targeted genomic enrichment with massively parallel sequencing (TGE+MPS) has emerged as the preferred method by which to provide comprehensive genetic testing for hearing loss. We aimed to identify CNVs in the STRC region using established and validated bioinformatics methods. METHODS: We used TGE+MPS to identify the genetic cause of hearing loss. The CNV results were confirmed with customized array comparative genomic hybridization (array CGH). RESULTS: Three probands with progressive mild to moderate hearing loss were found among 40 subjects with ARNSHL to segregate homozygous STRC deletions and gene to pseudogene conversion. Array CGH showed that the deletions/conversions span multiple genes outside of the exons captured by TGE+MPS. CONCLUSION: These data further validate the necessity to integrate the detection of both simple variant changes and complex genomic rearrangements in the clinical diagnosis of genetic hearing loss.

Deafness gene expression patterns in the mouse cochlea found by microarray analysis.

BACKGROUND: Tonotopy is one of the most fundamental principles of auditory function. While gradients in various morphological and physiological characteristics of the cochlea have been reported, little information is available on gradient patterns of gene expression. In addition, the audiograms in autosomal dominant non syndromic hearing loss can be distinctive, however, the mechanism that accounts for that has not been clarified. We thought that it is possible that tonotopic gradients of gene expression within the cochlea account for the distinct audiograms. METHODOLOGY/PRINCIPAL FINDINGS: We compared expression profiles of genes in the cochlea between the apical, middle, and basal turns of the mouse cochlea by microarray technology and quantitative RT-PCR. Of 24,547 genes, 783 annotated genes expressed more than 2-fold. The most remarkable finding was a gradient of gene expression changes in four genes (Pou4f3, Slc17a8, Tmc1, and Crym) whose mutations cause autosomal dominant deafness. Expression of these genes was greater in the apex than in the base. Interestingly, expression of the Emilin-2 and Tectb genes, which may have crucial roles in the cochlea, was also greater in the apex than in the base. CONCLUSIONS/SIGNIFICANCE: This study provides baseline data of gradient gene expression in the cochlea. Especially for genes whose mutations cause autosomal dominant non syndromic hearing loss (Pou4f3, Slc17a8, Tmc1, and Crym) as well as genes important for cochlear function (Emilin-2 and Tectb), gradual expression changes may help to explain the various pathological conditions.

A Japanese family showing high-frequency hearing loss with KCNQ4 and TECTA mutations.

CONCLUSIONS: We describe a Japanese family with high-frequency sensorineural hearing loss (SNHL) harboring a c.211delC mutation in the KCNQ4 gene. Families showing progressive high-frequency SNHL should be investigated for mutations in the KCNQ4 gene. OBJECTIVE: To determine the responsible deafness gene in a Japanese family with dominantly inherited high-frequency SNHL of unknown etiology. METHODS: We performed hearing tests for five members of the family, and the three affected with hearing loss underwent further audiological and vestibular examinations. Genetic analysis was performed to identify any possible causative mutations, as well as analysis of detailed clinical findings to determine the phenotype. RESULTS: The three affected subjects showed high-frequency SNHL. Extensive audiologic evaluation suggested cochlear involvement and progressive hearing loss. As for bilateral caloric testing, two of the three affected subjects showed hyporeflexia with recurrent vestibular symptoms. We identified the c.211delC mutation in the KCNQ4 gene and the c.2967C>A (p.H989Q) mutation in the TECTA gene. Based on the genotype-phenotype correlation, the c.211delC mutation in the KCNQ4 gene was associated with high-frequency SNHL in this family.

An Usher syndrome type 1 patient diagnosed before the appearance of visual symptoms by MYO7A mutation analysis.

Usher syndrome type 1 (USH1) appears to have only profound non-syndromic hearing loss in childhood and retinitis pigmentosa develops in later years. This study examined the frequency of USH1 before the appearance of visual symptoms in Japanese deaf children by MYO7A mutation analysis. We report the case of 6-year-old male with profound hearing loss, who did not have visual symptoms. The frequency of MYO7A mutations in profound hearing loss children is also discussed. We sequenced all exons of the MYO7A gene in 80 Japanese children with severe to profound non-syndromic HL not due to mutations of the GJB2 gene (ages 0-14 years). A total of nine DNA variants were found and six of them were presumed to be non-pathogenic variants. In addition, three variants of them were found in two patients (2.5%) with deafness and were classified as possible pathogenic variants. Among them, at least one nonsense mutation and one missense mutation from the patient were confirmed to be responsible for deafness. After MYO7A mutation analysis, the patient was diagnosed with RP, and therefore, also diagnosed with USH1. This is the first case report to show the advantage of MYO7A mutation analysis to diagnose USH1 before the appearance of visual symptoms. We believed that MYO7A mutation analysis is valid for the early diagnosis of USH1.

Comprehensive genetic screening of KCNQ4 in a large autosomal dominant nonsyndromic hearing loss cohort: genotype-phenotype correlations and a founder mutation.

The present study of KCNQ4 mutations was carried out to 1) determine the prevalence by unbiased population-based genetic screening, 2) clarify the mutation spectrum and genotype/phenotype correlations, and 3) summarize clinical characteristics. In addition, a review of the reported mutations was performed for better understanding of this deafness gene. The screening using 287 probands from unbiased Japanese autosomal dominant nonsyndromic hearing loss (ADNSHL) families identified 19 families with 7 different disease causing mutations, indicating that the frequency is 6.62% (19/287). While the majority were private mutations, one particular recurrent mutation, c.211delC, was observed in 13 unrelated families. Haplotype analysis in the vicinity of c.211delC suggests existence of a common ancestor. The majority of the patients showed all frequency, but high-frequency predominant, sensorineural hearing loss. The present study adds a new typical audiogram configuration characterized by mid-frequency predominant hearing loss caused by the p.V230E mutation. A variant at the N-terminal site (c. 211delC) showed typical ski-slope type audiogram configuration. Concerning clinical features, onset age was from 3 to 40 years old, and mostly in the teens, and hearing loss was gradually progressive. Progressive nature is a common feature of patients with KCNQ4 mutations regardless of the mutation type. In conclusion, KCNQ4 mutations are frequent among ADNSHL patients, and therefore screening of the gene and molecular confirmation of these mutations have become important in the diagnosis of these conditions.