Factors associated with Noninvasive ventilation compliance in patients with ALS/MND

Background: Although noninvasive ventilation (NIV) improves survival and quality of life (QOL) in ALS, use of NIV is suboptimal. Objective: To determine compliance with "early" NIV initiation, requisite for the feasibility of a large study of early NIV initiation, and examine factors impacting compliance. Methods: Seventy-three ALS participants with forced vital capacities (FVC) >50% were enrolled. Participants with FVC over 80% (Group 1) were initiated on NIV early (FVC between 80 and 85%). Participants with FVC between 50 and 80% (Group 2) started NIV at FVC between 50 and 55%. Symptom surveys, QOL scores, and NIV compliance (machine download documenting use ≥4 hours/night >60% of time) were collected following NIV initiation. Results: 53.6% of Group 1 and 50% of Group 2 were compliant 28 days following NIV initiation, with increased compliance over time. Participants who were unmarried, had lower income, lower educational attainment, or limited caregiver availability were less likely to be compliant. Bothersome symptoms in non-compliant participants included facial air pressure, frequent arousals with difficulty returning to sleep, and claustrophobia. Both compliant and noncompliant participants felt improved QOL with NIV; improvement was significantly greater in compliant participants. Conclusions: These data suggest ALS patients can comply with NIV early in their disease, and potentially benefit as evidenced by improved QOL scores, supporting both feasibility and need for a study comparing early versus late NIV initiation. Moreover, modifiable symptoms were identified that could be optimized to improve compliance. Further studies are needed to determine the impact of "early" intervention on survival and QOL.

Longitudinal associations between post-traumatic stress disorder and metabolic syndrome severity

BACKGROUND

Post-traumatic stress disorder (PTSD) is associated with elevated risk for metabolic syndrome (MetS). However, the direction of this association is not yet established, as most prior studies employed cross-sectional designs. The primary goal of this study was to evaluate bidirectional associations between PTSD and MetS using a longitudinal design.

METHOD

A total of 1355 male and female veterans of the conflicts in Iraq and Afghanistan underwent PTSD diagnostic assessments and their biometric profiles pertaining to MetS were extracted from the electronic medical record at two time points (spanning ~2.5 years, n = 971 at time 2).

RESULTS

The prevalence of MetS among veterans with PTSD was just under 40% at both time points and was significantly greater than that for veterans without PTSD; the prevalence of MetS among those with PTSD was also elevated relative to age-matched population estimates. Cross-lagged panel models revealed that PTSD severity predicted subsequent increases in MetS severity (β = 0.08, p = 0.002), after controlling for initial MetS severity, but MetS did not predict later PTSD symptoms. Logistic regression results suggested that for every 10 PTSD symptoms endorsed at time 1, the odds of a subsequent MetS diagnosis increased by 56%.

CONCLUSIONS

Results highlight the substantial cardiometabolic concerns of young veterans with PTSD and raise the possibility that PTSD may predispose individuals to accelerated aging, in part, manifested clinically as MetS. This demonstrates the need to identify those with PTSD at greatest risk for MetS and to develop interventions that improve both conditions.

Linkage and association of successful aging to the 6q25 region in large Amish kindreds

Successful aging (SA) is a multidimensional phenotype involving living to older age with high physical function, preserved cognition, and continued social engagement. Several domains underlying SA are heritable, and identifying health-promoting polymorphisms and their interactions with the environment could provide important information regarding the health of older adults. In the present study, we examined 263 cognitively intact Amish individuals age 80 and older (74 SA and 189 "normally aged") all of whom are part of a single 13-generation pedigree. A genome-wide association study of 630,309 autosomal single nucleotide polymorphisms (SNPs) was performed and analyzed for linkage using multipoint analyses and for association using the modified quasi-likelihood score test. There was evidence for linkage on 6q25-27 near the fragile site FRA6E region with a dominant model maximum multipoint heterogeneity LOD score = 3.2. The 1-LOD-down support interval for this linkage contained one SNP for which there was regionally significant evidence of association (rs205990, p = 2.36 × 10(-5)). This marker survived interval-wide Bonferroni correction for multiple testing and was located between the genes QKI and PDE10A. Other areas of chromosome 6q25-q27 (including the FRA6E region) contained several SNPs associated with SA (minimum p = 2.89 × 10(-6)). These findings suggest potentially novel genes in the 6q25-q27 region linked and associated with SA in the Amish; however, these findings should be verified in an independent replication cohort.

Successful aging shows linkage to chromosomes 6, 7, and 14 in the Amish

Successful aging (SA) is a multidimensional phenotype involving preservation of cognitive ability, physical function, and social engagement throughout life. Multiple components of SA are heritable, supporting a genetic component. The Amish are genetically and socially isolated with homogeneous lifestyles, making them a suitable population for studying the genetics of SA. DNA and measures of SA were collected on 214 cognitively intact Amish individuals over age 80. Individuals were grouped into a 13-generation pedigree using the Anabaptist Genealogy Database. A linkage screen of 5944 single nucleotide polymorphisms (SNPs) was performed using 12 informative subpedigrees with an affected-only 2-point and multipoint linkage analysis. Eleven SNPs produced 2-point LOD scores >2, suggestive of linkage. Multipoint linkage analyses, allowing for heterogeneity, detected significant LOD scores on chromosomes 6 (HLOD = 4.50), 7 (LOD*= 3.11), and 14 (HLOD = 4.17), suggesting multiple new loci underlying SA.

A genome-wide linkage screen in the Amish with Parkinson disease points to chromosome 6

Parkinson disease (PD) is a common complex neurodegenerative disorder with an underlying genetic etiology that has been difficult to dissect. Although some PD risk genes have been discovered, most of the underlying genetic etiology remains unknown. To further elucidate the genetic component, we have undertaken a genome-wide linkage screen in an isolated founder population of Amish living in the Midwestern United States. We performed tests for linkage and for association using a marker set of nearly 6000 single-nucleotide polymorphisms. Parametric multipoint linkage analysis generated a logarithm of the odds of linkage (LOD) score of 2.44 on chromosome 6 in the SYNE1 gene, approximately 8 Mbp from the PARK2 gene. In a different region on chromosome 6 (∼67 Mbp from PARK2) an association was found for rs4302647 (p < 4.0 × 10(-6) ), which is not within 300 kb of any gene. While the association exceeds Bonferroni correction, it may yet represent a false positive due to the small sample size and the low minor allele frequency. The minor allele frequency in affecteds is 0.07 compared to 0.01 in unaffecteds. Taken together, these results support involvement of loci on chromosome 6 in the genetic etiology of PD.

Distinct roles for CARMIL isoforms in cell migration

Molecular mechanisms for cell migration, especially how signaling and cytoskeletal systems are integrated, are not understood well. Here, we examined the role of CARMIL (capping protein, Arp2/3, and Myosin-I linker) family proteins in migrating cells. Vertebrates express three conserved genes for CARMIL, and we examined the functions of the two CARMIL genes expressed in migrating human cultured cells. Both isoforms, CARMIL1 and 2, were necessary for cell migration, but for different reasons. CARMIL1 localized to lamellipodia and macropinosomes, and loss of its function caused loss of lamellipodial actin, along with defects in protrusion, ruffling, and macropinocytosis. CARMIL1-knockdown cells showed loss of activation of Rac1, and CARMIL1 was biochemically associated with the GEF Trio. CARMIL2, in contrast, colocalized with vimentin intermediate filaments, and loss of its function caused a distinctive multipolar phenotype. Loss of CARMIL2 also caused decreased levels of myosin-IIB, which may contribute to the polarity phenotype. Expression of one CARMIL isoform was not able to rescue the knockdown phenotypes of the other. Thus, the two isoforms are both important for cell migration, but they have distinct functions.

Practice parameter update: the care of the patient with amyotrophic lateral sclerosis: multidisciplinary care, symptom management, and cognitive/behavioral impairment (an evidence-based review): report of the Quality Standards Subcommittee of the American Academy of Neurology

OBJECTIVE

To systematically review evidence bearing on the management of patients with amyotrophic lateral sclerosis (ALS).

METHODS

The authors analyzed studies from 1998 to 2007 to update the 1999 practice parameter. Topics covered in this section include breaking the news, multidisciplinary clinics, symptom management, cognitive and behavioral impairment, communication, and palliative care for patients with ALS.

RESULTS

The authors identified 2 Class I studies, 8 Class II studies, and 30 Class III studies in ALS, but many important areas have been little studied. More high-quality, controlled studies of symptomatic therapies and palliative care are needed to guide management and assess outcomes in patients with ALS.

RECOMMENDATIONS

Multidisciplinary clinic referral should be considered for managing patients with ALS to optimize health care delivery and prolong survival (Level B) and may be considered to enhance quality of life (Level C). For the treatment of refractory sialorrhea, botulinum toxin B should be considered (Level B) and low-dose radiation therapy to the salivary glands may be considered (Level C). For treatment of pseudobulbar affect, dextromethorphan and quinidine should be considered if approved by the US Food and Drug Administration (Level B). For patients who develop fatigue while taking riluzole, withholding the drug may be considered (Level C). Because many patients with ALS demonstrate cognitive impairment, which in some cases meets criteria for dementia, screening for cognitive and behavioral impairment should be considered in patients with ALS (Level B). Other management strategies all lack strong evidence.

Practice parameter update: the care of the patient with amyotrophic lateral sclerosis: drug, nutritional, and respiratory therapies (an evidence-based review): report of the Quality Standards Subcommittee of the American Academy of Neurology

OBJECTIVE

To systematically review evidence bearing on the management of patients with amyotrophic lateral sclerosis (ALS).

METHODS

The authors analyzed studies from 1998 to 2007 to update the 1999 practice parameter. Topics covered in this section include slowing disease progression, nutrition, and respiratory management for patients with ALS.

RESULTS

The authors identified 8 Class I studies, 5 Class II studies, and 43 Class III studies in ALS. Important treatments are available for patients with ALS that are underutilized. Noninvasive ventilation (NIV), percutaneous endoscopic gastrostomy (PEG), and riluzole are particularly important and have the best evidence. More studies are needed to examine the best tests of respiratory function in ALS, as well as the optimal time for starting PEG, the impact of PEG on quality of life and survival, and the effect of vitamins and supplements on ALS.

RECOMMENDATIONS

Riluzole should be offered to slow disease progression (Level A). PEG should be considered to stabilize weight and to prolong survival in patients with ALS (Level B). NIV should be considered to treat respiratory insufficiency in order to lengthen survival (Level B) and to slow the decline of forced vital capacity (Level B). NIV may be considered to improve quality of life (Level C) [corrected].Early initiation of NIV may increase compliance (Level C), and insufflation/exsufflation may be considered to help clear secretions (Level C).

Autosomal-dominant distal myopathy associated with a recurrent missense mutation in the gene encoding the nuclear matrix protein, matrin 3

Distal myopathies represent a heterogeneous group of inherited skeletal muscle disorders. One type of adult-onset, progressive autosomal-dominant distal myopathy, frequently associated with dysphagia and dysphonia (vocal cord and pharyngeal weakness with distal myopathy [VCPDM]), has been mapped to chromosome 5q31 in a North American pedigree. Here, we report the identification of a second large VCPDM family of Bulgarian descent and fine mapping of the critical interval. Sequencing of positional candidate genes revealed precisely the same nonconservative S85C missense mutation affecting an interspecies conserved residue in the MATR3 gene in both families. MATR3 is expressed in skeletal muscle and encodes matrin 3, a component of the nuclear matrix, which is a proteinaceous network that extends throughout the nucleus. Different disease related haplotype signatures in the two families provided evidence that two independent mutational events at the same position in MATR3 cause VCPDM. Our data establish proof of principle that the nuclear matrix is crucial for normal skeletal muscle structure and function and put VCPDM on the growing list of monogenic disorders associated with the nuclear proteome.

Germline CDH1 deletions in hereditary diffuse gastric cancer families

Germline CDH1 point or small frameshift mutations can be identified in 30-50% of hereditary diffuse gastric cancer (HDGC) families. We hypothesized that CDH1 genomic rearrangements would be found in HDGC and identified 160 families with either two gastric cancers in first-degree relatives and with at least one diffuse gastric cancer (DGC) diagnosed before age 50, or three or more DGC in close relatives diagnosed at any age. Sixty-seven carried germline CDH1 point or small frameshift mutations. We screened germline DNA from the 93 mutation negative probands for large genomic rearrangements by Multiplex Ligation-Dependent Probe Amplification. Potential deletions were validated by RT-PCR and breakpoints cloned using a combination of oligo-CGH-arrays and long-range-PCR. In-silico analysis of the CDH1 locus was used to determine a potential mechanism for these rearrangements. Six of 93 (6.5%) previously described mutation negative HDGC probands, from low GC incidence populations (UK and North America), carried genomic deletions (UK and North America). Two families carried an identical deletion spanning 193 593 bp, encompassing the full CDH3 sequence and CDH1 exons 1 and 2. Other deletions affecting exons 1, 2, 15 and/or 16 were identified. The statistically significant over-representation of Alus around breakpoints indicates it as a likely mechanism for these deletions. When all mutations and deletions are considered, the overall frequency of CDH1 alterations in HDGC is approximately 46% (73/160). CDH1 large deletions occur in 4% of HDGC families by mechanisms involving mainly non-allelic homologous recombination in Alu repeat sequences. As the finding of pathogenic CDH1 mutations is useful for management of HDGC families, screening for deletions should be offered to at-risk families.

Inclusion body myositis functional rating scale: a reliable and valid measure of disease severity

We developed a disease-specific, 10-point functional rating scale for patients with inclusion body myositis (IBMFRS). The IBMFRS was utilized as a secondary outcome measure in a multicenter pilot trial of the clinical safety and tolerability of high-dose beta interferon-1a. In this trial, 28 IBM patients completed the IBMFRS at baseline and monthly for 6 months. The IBMFRS showed statistically significant correlations (P < 0.001) with maximal voluntary isometric contraction, manual muscle testing, handgrip dynamometry, and the amyotrophic lateral sclerosis (ALS) functional rating scale (ALSPRS). Compared to these other outcome measures, the IBMFRS was also the most sensitive measure of change over the course of the study.

Myotilin is not the causative gene for vocal cord and pharyngeal weakness with distal myopathy (VCPDM)

Myotilin (MYOT) is a promising candidate gene for Vocal Cord and Pharyngeal Weakness with Distal Myopathy (VCPDM, also known as MPD2). Located within the minimum VCPDM candidate interval, myotilin mutations also cause a similarly progressive and adult-onset muscle disease. We examined myotilin in VCPDM patients by sequence analysis, RT-PCR, Southern blotting, and western blotting. We detected no defects in the myotilin gene, transcript, or protein in VCPDM. We also report several useful SNPs and STRs for the analysis of myotilin in muscle diseases of suspected, yet unknown genetic origin. We conclude that MYOT mutations likely are not a cause of VCPDM.

A genome-wide linkage analysis of dementia in the Amish

Susceptibility genes for Alzheimer's disease are proving to be highly challenging to detect and verify. Population heterogeneity may be a significant confounding factor contributing to this difficulty. To increase the power for disease susceptibility gene detection, we conducted a genome-wide genetic linkage screen using individuals from the relatively isolated, genetically homogeneous, Amish population. Our genome linkage analysis used a 407-microsatellite-marker map (average density 7 cM) to search for autosomal genes linked to dementia in five Amish families from four Midwestern U.S. counties. Our highest two-point lod score (3.01) was observed at marker D4S1548 on chromosome 4q31. Five other regions (10q22, 3q28, 11p13, 4q28, 19p13) also demonstrated suggestive linkage with markers having two-point lod scores >2.0. While two of these regions are novel (4q31 and 11p13), the other regions lie close to regions identified in previous genome scans in other populations. Our results identify regions of the genome that may harbor genes involved in a subset of dementia patients, in particular the North American Amish community.

Combinatorial Mismatch Scan (CMS) for loci associated with dementia in the Amish

BACKGROUND

Population heterogeneity may be a significant confounding factor hampering detection and verification of late onset Alzheimer's disease (LOAD) susceptibility genes. The Amish communities located in Indiana and Ohio are relatively isolated populations that may have increased power to detect disease susceptibility genes.

METHODS

We recently performed a genome scan of dementia in this population that detected several potential loci. However, analyses of these data are complicated by the highly consanguineous nature of these Amish pedigrees. Therefore we applied the Combinatorial Mismatch Scanning (CMS) method that compares identity by state (IBS) (under the presumption of identity by descent (IBD)) sharing in distantly related individuals from such populations where standard linkage and association analyses are difficult to implement. CMS compares allele sharing between individuals in affected and unaffected groups from founder populations. Comparisons between cases and controls were done using two Fisher's exact tests, one testing for excess in IBS allele frequency and the other testing for excess in IBS genotype frequency for 407 microsatellite markers.

RESULTS

In all, 13 dementia cases and 14 normal controls were identified who were not related at least through the grandparental generation. The examination of allele frequencies identified 24 markers (6%) nominally (p < or = 0.05) associated with dementia; the most interesting (empiric p < or = 0.005) markers were D3S1262, D5S211, and D19S1165. The examination of genotype frequencies identified 21 markers (5%) nominally (p < or = 0.05) associated with dementia; the most significant markers were both located on chromosome 5 (D5S1480 and D5S211). Notably, one of these markers (D5S211) demonstrated differences (empiric p < or = 0.005) under both tests.

CONCLUSION

Our results provide the initial groundwork for identifying genes involved in late-onset Alzheimer's disease within the Amish community. Genes identified within this isolated population will likely play a role in a subset of late-onset AD cases across more general populations. Regions highlighted by markers demonstrating suggestive allelic and/or genotypic differences will be the focus of more detailed examination to characterize their involvement in dementia.

Characterization of a recurrent germ line mutation of the E-cadherin gene: implications for genetic testing and clinical management

PURPOSE

To identify germ line CDH1 mutations in hereditary diffuse gastric cancer (HDGC) families and develop guidelines for management of at risk individuals.

EXPERIMENTAL DESIGN

We ascertained 31 HDGC previously unreported families, including 10 isolated early-onset diffuse gastric cancer (DGC) cases. Screening for CDH1 germ line mutations was done by denaturing high-performance liquid chromatography and automated DNA sequencing.

RESULTS

We identified eight inactivating and one missense CDH1 germ line mutation. The missense mutation conferred in vitro loss of protein function. Two families had the previously described 1003C>T nonsense mutation. Haplotype analysis revealed this to be a recurrent and not a founder mutation. Thirty-six percent (5 of 14) of the families with a documented DGC diagnosed before the age of 50 and other cases of gastric cancer carried CDH1 germ line mutations. Two of 10 isolated cases of DGC in individuals ages <35 years harbored CDH1 germ line mutations. One mutation positive family was ascertained through a family history of lobular breast cancer (LBC) and another through an individual with both DGC and LBC. Occult DGC was identified in five of six prophylactic gastrectomies done on asymptomatic, endoscopically negative 1003C>T mutation carriers.

CONCLUSIONS

In addition to families with a strong history of early-onset DGC, CDH1 mutation screening should be offered to isolated cases of DGC in individuals ages <35 years and for families with multiple cases of LBC, with any history of DGC or unspecified GI malignancies. Prophylactic gastrectomy is potentially a lifesaving procedure and clinical breast screening is recommended for asymptomatic mutation carriers.

Maternal lineages and Alzheimer disease risk in the Old Order Amish

Old Order Amish, founded by a small number of Swiss immigrants, exist in culturally isolated communities across rural North America. The consequences of genetic isolation and inbreeding within this group are evident by increased frequencies of many monogenic diseases and several complex disorders. Conversely, the prevalence of Alzheimer disease (AD), the most common form of dementia, is lower in the Amish than in the general American population. Since mitochondrial dysfunction has been proposed as an underlying cause of AD and a specific haplogroup was found to affect AD susceptibility in Caucasians, we investigated whether inherited mitochondrial haplogroups affect risk of developing AD dementia in Ohio and Indiana Amish communities. Ninety-five independent matrilines were observed across six large pedigrees and three small pedigrees then classified into seven major European haplogroups. Haplogroup T is the most frequent haplogroup represented overall in these maternal lines (35.4%) while observed in only 10.6% in outbred American and European populations. Furthermore, haplogroups J and K are less frequent (1.0%) than in the outbred data set (9.4-11.2%). Affected case matrilines and unaffected control lines were chosen from pedigrees to test whether specific haplogroups and their defining SNPs confer risk of AD. We did not observe frequency differences between AD cases compared to controls overall or when stratified by sex. Therefore, we suggest that the genetic effect responsible for AD dementia in the affected Amish pedigrees is unlikely to be of mitochondrial origin and may be caused by nuclear genetic factors.

An autosomal genomic screen for dementia in an extended Amish family

Apolipoprotein E (APOE) is the only universally confirmed susceptibility gene for late-onset Alzheimer disease (LOAD), although many loci are believed to modulate LOAD risk. The genetic homogeneity of isolated populations, such as the Amish, potentially provide increased power to identify LOAD susceptibility genes. Population homogeneity in these special populations may reduce the total number of susceptibility genes contributing to the complex disorder, thereby increasing the ability to identify any one susceptibility gene. Dementia in the Amish is clinically indistinguishable from LOAD in the general population. Previous studies in the Amish demonstrated a significantly decreased frequency of the APOE-4 susceptibility allele, but significant familial clustering of dementia [M.A. Pericak-Vance, C.C. Johnson, J.B. Rimmler, A.M. Saunders, L.C. Robinson, E.G. D'Hondt, C.E. Jackson, J.L. Haines, Alzheimer's disease and apolipoprotein E-4 allele in an Amish population, Ann. Neurol. 39 (1996) 700-704]. These data suggested that a genetic etiology independent of APOE may underlie the dementia observed in this population. In the present analysis, we focused on a large, multiplex, inbred Amish family (24 sampled individuals; 10 of whom are affected). We completed a genomic screen to identify novel LOAD loci (n=316 genetic markers), using both model-dependent "affecteds-only" analysis (dominant and recessive) and model-independent affected relative pair analysis. Interesting results (lod>1.5 or p<0.01) were obtained for markers on eight chromosomes (2q, 5q, 6q, 7p, 8p, 8q, 11p, 18p, 18q, and 19q). The highest overall score was a multipoint lod score of 3.1 on chromosome 11p. Most regions we identified were not previously detected by genomic screens of outbred populations and may represent population-specific susceptibilities to LOAD. These loci are currently under further investigation in a study of LOAD including additional Amish families.

Amish brittle hair syndrome gene maps to 7p14.1

The brittle hair syndrome (BHS) is characterized by short stature, intellectual impairment, brittle hair, and decreased fertility in 20 members from a large Amish consanguineous kindred previously reported affected with this syndrome. We mapped the BHS gene by genome scan to chromosome 7p14.1. Evidence of linkage was supported by a maximum multipoint LOD score of 6 obtained with GENEHUNTER for the linkage interval defined by markers D7S484-D7S2422 distant by 17.2 cM. Two-point linkage analysis performed with SUPERLINK yielded a LOD score of 9.02 at theta = 0 for marker D7S2497 located within that interval. Analysis of haplotypes homozygous-by-descent allowed fine mapping of the BHS gene within a 4.81 cM interval delimited by markers D7S2497 and D7S691, a region that spreads over 3.42 Mb.

Identification of C7orf11 (TTDN1) gene mutations and genetic heterogeneity in nonphotosensitive trichothiodystrophy

We have identified C7orf11, which localizes to the nucleus and is expressed in fetal hair follicles, as the first disease gene for nonphotosensitive trichothiodystrophy (TTD). C7orf11 maps to chromosome 7p14, and the disease locus has been designated "TTDN1" (TTD nonphotosensitive 1). Mutations were found in patients with Amish brittle-hair syndrome and in other nonphotosensititive TTD cases with mental retardation and decreased fertility but not in patients with Sabinas syndrome or Pollitt syndrome. Therefore, genetic heterogeneity in nonphotosensitive TTD is a feature similar to that observed in photosensitive TTD, which is caused by mutations in transcription factor II H (TFIIH) subunit genes. Comparative immunofluorescence analysis, however, suggests that C7orf11 does not influence TFIIH directly. Given the absence of cutaneous photosensitivity in the patients with C7orf11 mutations, together with the protein's nuclear localization, C7orf11 may be involved in transcription but not DNA repair.

Uterine tumours are a phenotypic manifestation of the hyperparathyroidism-jaw tumour syndrome

The hyperparathyroidism-jaw tumour (HPT-JT) syndrome is an autosomal dominant disorder characterized by parathyroid tumours, which are frequently carcinomas, and ossifying jaw fibromas. In addition, some patients may develop renal tumours and cysts. The gene causing HPT-JT, which is referred to as HRPT2 and is located on chromosome 1q31.2, encodes a 531 amino acid protein called PARAFIBROMIN. To date 42 mutations, of which 22 are germline, have been reported and 97% of these are inactivating and consistent with a tumour suppressor role for HRPT2. We have investigated another four HPT-JT families for germline mutations, searched for additional clinical phenotypes, and examined for a genotype-phenotype correlation. Mutations were found in two families. One family had a novel deletional-insertion at codon 669, and the other had a 2 bp insertion at codon 679, which has been reported in four other unrelated patients. These five unrelated patients and their families with the same mutation were not found to develop the same tumours, thereby indicating an absence of a genotype-phenotype correlation. An analysis of 33 HPT-JT kindreds revealed that affected women in 13 HPT-JT families suffered from menorrhagia in their second to fourth decades. This often required hysterectomy, which revealed the presence of uterine tumours. This resulted in a significantly reduced maternal transmission of the disease. Thus, the results of our analysis expand the spectrum of HPT-JT-associated tumours to include uterine tumours, and these may account for the decreased reproductive fitness in females from HPT-JT families.

Germline E-cadherin mutations in hereditary diffuse gastric cancer: assessment of 42 new families and review of genetic screening criteria

BACKGROUND

Mutations in the E-cadherin (CDH1) gene are a well documented cause of hereditary diffuse gastric cancer (HDGC). Development of evidence based guidelines for CDH1 screening for HDGC have been complicated by its rarity, variable penetrance, and lack of founder mutations.

METHODS

Forty three new gastric cancer (GC) families were ascertained from multiple sources. In 42 of these families at least one gastric cancer was pathologically confirmed to be a diffuse gastric cancer (DGC); the other family had intestinal type gastric cancers. Screening of the entire coding region of the CDH1 gene and all intron/exon boundaries was performed by bi-directional sequencing.

RESULTS

Novel mutations were found in 13 of the 42 DGC families (31% overall). Twelve of these mutations occur among the 25 families with multiple cases of gastric cancer and with pathologic confirmation of diffuse gastric cancer phenotype in at least one individual under the age of 50 years. The mutations found include small insertions and deletions, splice site mutations, and three non-conservative amino acid substitutions (A298T, W409R, and R732Q). All three missense mutations conferred loss of E-cadherin function in in vitro assays. Multiple cases of breast cancers including pathologically confirmed lobular breast cancers were observed both in mutation positive and negative families.

CONCLUSION

Germline truncating CDH1 mutations are found in 48% of families with multiple cases of gastric cancer and at least one documented case of DGC in an individual under 50 years of age. We recommend that these criteria be used for selecting families for CDH1 mutational analysis.

HRPT2, encoding parafibromin, is mutated in hyperparathyroidism-jaw tumor syndrome

We report here the identification of a gene associated with the hyperparathyroidism-jaw tumor (HPT-JT) syndrome. A single locus associated with HPT-JT (HRPT2) was previously mapped to chromosomal region 1q25-q32. We refined this region to a critical interval of 12 cM by genotyping in 26 affected kindreds. Using a positional candidate approach, we identified thirteen different heterozygous, germline, inactivating mutations in a single gene in fourteen families with HPT-JT. The proposed role of HRPT2 as a tumor suppressor was supported by mutation screening in 48 parathyroid adenomas with cystic features, which identified three somatic inactivating mutations, all located in exon 1. None of these mutations were detected in normal controls, and all were predicted to cause deficient or impaired protein function. HRPT2 is a ubiquitously expressed, evolutionarily conserved gene encoding a predicted protein of 531 amino acids, for which we propose the name parafibromin. Our findings suggest that HRPT2 is a tumor-suppressor gene, the inactivation of which is directly involved in predisposition to HPT-JT and in development of some sporadic parathyroid tumors.

Frequent occurrence of an intron 4 mutation in multiple endocrine neoplasia type 1

MEN1 is an autosomal dominant disorder characterized by parathyroid, pituitary, and pancreatic tumors. The MEN1 gene is located on chromosome 11q13 and encodes a 610-amino acid protein. MEN1 mutations are of diverse types and are scattered throughout the coding region, such that almost every MEN1 family will have its individual mutation. To further characterize such mutations we ascertained 34 unrelated MEN1 probands and undertook DNA sequence analysis. This identified 17 different mutations in 24 probands (2 nonsense, 2 missense, 2 in-frame deletions, 5 frameshift deletions, 1 frameshift deletional-insertion, 3 frameshift insertions, 1 donor splice site mutation, and a g-->a transition that resulted in a novel acceptor splice site in intron 4). The intron 4 mutation was found in 7 unrelated families, and the tumors in these families varied considerably, indicating a lack of genotype-phenotype correlation. However, this intron 4 mutation is the most frequently occurring germline MEN1 mutation ( approximately 10% of all mutations), and together with 5 others at codons 83-84, 118-119, 209-211, 418, and 516, accounts for 36.6% of all mutations, a finding that indicates an approach for identifying the widely diverse MEN1 mutations.

Screening E-cadherin in gastric cancer families reveals germline mutations only in hereditary diffuse gastric cancer kindred

The International Gastric Cancer Linkage Consortium (IGCLC) predicted that up to 25% of families fulfilling the criteria for hereditary diffuse gastric cancer (HDGC) would harbor CDH1 germline mutations. This was based on observations from the low number of diffuse gastric cancer families described at the time, and its validation would require analysis of larger numbers. Here we report the results of germline CDH1 mutation screening in 39 kindred with familial aggregation of gastric cancer, a subset of which fulfills the criteria defined by the IGCLC for HDGC. CDH1 germline mutations were detected in four of 11 (36.4%) HDGC families. No mutations were identified in 63.6% of HDGC families or in kindred with familial aggregation of gastric cancer not fulfilling criteria for HDGC. These results add support to the evidence that only HDGC families harbor germline mutations in CDH1 and that genes other than CDH1 remain to be identified.

A preliminary evaluation of a prospective study of pulmonary function studies and symptoms of hypoventilation in ALS/MND patients

There is still no consensus as to which physiologic marker should be used as a trigger for the initiation of non-invasive positive pressure ventilation (NPPV) in patients with amyotrophic lateral sclerosis (ALS). Current practice parameters recommend that the decision to begin treatment be based upon forced vital capacity (FVC) measurements. A prospective, randomized study was performed in 20 ALS patients who had an FVC of 70-100%. Patients received baseline assessments including: ALS functional rating scale-respiratory version (ALSFRS-R), pulmonary symptom scale, Short form 36 (SF-36), FVC%, maximal inspiratory pressure (MIP), maximal expiratory pressure (MEP), and nocturnal oximetry. Patients were randomized to receive NPPV based upon nocturnal oximetry studies suggesting oxygen desaturation <90% for one cumulative minute ("early intervention") or a FVC <50% ("standard of care"). At enrollment, there was no significant correlation between FVC% and the ALSFRS-R, symptom score, MEP, MIP, or duration of nocturnal desaturation <90%. An increase in the vitality subscale of the SF-36 was demonstrated in 5/6 patients randomized to "early intervention" with NPPV. Our data indicate that FVC% correlates poorly with respiratory symptoms and suggests that MIP and nocturnal oximetry may be more sensitive measures of early respiratory insufficiency. In addition, intervention with NPPV earlier than our current standard of care may result in improved quality of life.

Inactivation of the E-cadherin gene in sporadic diffuse-type gastric cancer

Loss of the cell adhesion molecule E-cadherin has been observed in a variety of human carcinomas, and germline E-cadherin mutations have been found in several familial cases of diffuse gastric cancer. We sought to determine the prevalence and nature of E-cadherin alterations in "sporadic" gastric carcinomas. We performed comprehensive sequencing of the coding region, loss of heterozygosity (LOH) analysis, and immunohistochemical protein expression determination on 40 sporadic gastric adenocarcinomas. In total, 7 of 25 diffuse-type cancers harbored genetic alterations in the E-cadherin gene. Novel mutations predicted to significantly compromise protein function were found within 4 of these cancers, 2 of which harbored alterations resulting in biallelic inactivation of the gene product. Three diffuse cancers failed to amplify Exon 8 of E-cadherin, suggesting the presence of a homozygous abnormality. Notably, one germline E-cadherin mutation was also identified within these "sporadic" diffuse cancers. Significant gene mutations were not found in the 14 intestinal-type or histologically mixed cancer. Immunohistochemistry revealed aberrant or negative protein expression in seven diffuse-type tumors, four of which correlated with the genetic alterations. Both diffuse and intestinal-type tumors exhibited low rates of LOH, suggesting that allelic loss at the locus is not a common mechanism for E-cadherin inactivation during gastric tumorigenesis. Our observations suggest that inactivation of the E-cadherin gene occurs only in a subset of diffuse-type gastric cancers, as the majority of cases did not contain genetic alterations or identifiable protein abnormalities. Germline E-cadherin alterations, although rare, may underlie some diffuse gastric cancer cases that have important biologic and practical implications

Prophylactic total gastrectomy for familial gastric cancer

BACKGROUND

An autosomal dominant syndrome of diffuse gastric cancer has been reported with germline mutations in the E-cadherin (CDH1) gene and has been identified in approximately 14 families and 50 individuals worldwide. Penetrance of the gene is 70% to 80%, and the average age of onset of gastric cancer is 37 years. These characteristics have led to the consideration of prophylactic total gastrectomy in family members with CDH1 mutations.

METHODS

We report here the first use of prophylactic gastrectomy in 6 asymptomatic members of 2 families (2 males, 4 females; ages 22, 27, 28, 35, 39, and 40) based on family pedigree and genetic analysis. Total gastrectomy was performed via an upper midline incision, and reconstruction of the gastrointestinal tract was done via a Roux-en-Y esophagojejunostomy. Complete removal of all gastric mucosa was documented intraoperatively, and confirmation was made that only esophageal mucosa remained at the proximal specimen margin.

RESULTS

The gastric specimens appeared normal, and the results of routine pathologic examination were negative for cancer. All specimens from patients who tested positive for E-cadherin mutations were subjected to a research protocol of microscopic sectioning in which 150 to 250 tissue blocks were examined. All of these patients had microscopic foci of cancer, often at multiple sites, with overlying normal gastric mucosa.

CONCLUSIONS

E-cadherin gene mutations in association with familial gastric cancer is a new disease for which prophylactic surgery must be considered. The morbidity of this operation is much higher than that for other genetic diseases, but the alternative is a mortality risk of more than 80% at a young age.

The development of lymphomas in families with autoimmune lymphoproliferative syndrome with germline Fas mutations and defective lymphocyte apoptosis

Lymphomas were studied in kindreds with autoimmune lymphoproliferative syndrome (ALPS; Canale-Smith syndrome), a disorder of lymphocyte homeostasis usually associated with germline Fas mutations. Fas (CD95/APO-1) is a cell surface receptor that initiates programmed cell death, or apoptosis, of activated lymphocytes. Lymphoma phenotype was determined by immunohistochemistry, frequency of CD3(+)CD4(-)CD8(-) T-cell-receptor alpha/beta cells by flow cytometry, nucleotide sequences of the gene encoding Fas (APT1, TNFRSF6), and the percentage of lymphocytes undergoing apoptosis in vitro. Of 223 members of 39 families, 130 individuals possessed heterozygous germline Fas mutations. Eleven B-cell and T-cell lymphomas of diverse types developed in 10 individuals with mutations in 8 families, up to 48 years after lymphoproliferation was first documented. Their risk of non-Hodgkin and Hodgkin lymphomas, respectively, was 14 and 51 times greater than expected (each P <.001). Investigation of these 10 patients and their relatives with Fas mutations revealed that all had defective lymphocyte apoptosis and most had other features of ALPS. The tumor cells retained the heterozygous Fas mutations found in the peripheral blood and manifested defective Fas-mediated killing. These data implicate a role for Fas-mediated apoptosis in preventing B-cell and T-cell lymphomas. Inherited defects in receptor-mediated lymphocyte apoptosis represent a newly appreciated risk factor for lymphomas.

Early gastric cancer in young, asymptomatic carriers of germ-line E-cadherin mutations

BACKGROUND

Germ-line truncating mutations in the E-cadherin (CDH1) gene have been found in families with hereditary diffuse gastric cancer. These families are characterized by a highly penetrant susceptibility to diffuse gastric cancer with an autosomal dominant pattern of inheritance, predominantly in young persons. We describe genetic screening, surgical management, and pathological findings in young persons with truncating mutations in CDH1 from two unrelated families with hereditary diffuse gastric cancer.

METHODS

Mutation-specific predictive genetic testing was performed by polymerase-chain-reaction amplification, followed by restriction-enzyme digestion and DNA sequencing in Family 1 and by heteroduplex analysis in Family 2. A total gastrectomy was performed prophylactically in five carriers of mutations who were between 22 and 40 years old. In each case, the entire mucosa of the stomach was extensively sampled for microscopical analysis.

RESULTS

Superficial infiltrates of malignant signet-ring cells were identified in the surgical samples from all five persons who underwent gastrectomy. These early diffuse gastric cancers were multifocal in three of the five cases, and in one person infiltrates of malignant signet-ring cells were present in 65 of the 140 tissue blocks analyzed, representing in aggregate less than 2 percent of the gastric mucosa.

CONCLUSIONS

We recommend genetic counseling and consideration of prophylactic gastrectomy in young, asymptomatic carriers of germ-line truncating CDH1 mutations who belong to families with highly penetrant hereditary diffuse gastric cancer.

Motor neuron disease

Motor neuron disease refers to a spectrum of disorders resulting from degeneration of the upper or lower motor neurons or both. Amyotrophic lateral sclerosis is the most common form of motor neuron disease, in which patients demonstrate evidence of both anterior horn cell (lower motor neuron) and corticospinal tract (upper motor neuron) dysfunction. Several theories regarding the pathogenesis of amyotrophic lateral sclerosis have emerged, including glutamate excitotoxicity, free radical oxidative stress, cytoskeletal abnormalities, a deficiency of neurotrophic factor, autoimmunity, apoptosis, and viral infection. Numerous clinical trials have been completed based on these possible mechanisms of the disease propagation including treatment with antiglutamate agents, anti-oxidants, immunosuppressants, and neurotrophic factors. Several of these trials have shown modest effects in slowing the disease course. None, however, have yielded marked benefit in arresting disease progression. The most significant effect in abating disease progression has been our use and understanding of aggressive symptomatic therapy to reduce disability, enhance quality of life, and improve prognosis.

Randomized controlled trial of IVIg in untreated chronic inflammatory demyelinating polyradiculoneuropathy

OBJECTIVE

To determine the efficacy of IV immunoglobulin (IVIg) given patients with untreated chronic inflammatory demyelinating polyradiculoneuropathy (CIDP).

METHODS

A randomized, double-blind, multicenter, investigator-initiated study compared IVIg (Aventis Behring LLC, King of Prussia, PA) with placebo (5% albumin). On days 1, 2, and 21, IVIg (1 g/kg) or placebo was given. The primary outcome measure was the change in muscle strength from baseline to day 42, using the average muscle score (AMS). Secondary outcome measures included change from baseline AMS at days 10 and 21, the Hughes' functional disability scale, forced vital capacity (FVC), and nerve conduction studies (NCS) of four motor nerves (median, ulnar, peroneal, and tibial).

RESULTS

The patients (n = 33) were randomized. Of these, 30 (14 women, 16 men, aged 54 +/- 20 years, range 13 to 82) received IVIg and 23 were given placebo (12 women, 11 men, aged 50 +/- 18 years, range 23 to 73). Baseline AMS values of the groups were similar (IVIg 7.06 +/- 1.31 versus placebo 7.28 +/- 1.18, p = 0.53). There were two dropouts in placebo group and one in the IVIg group. Mean AMS improved at day 42 comparing IVIg with placebo (0.63 versus -0.1, p = 0.006). Improved strength was seen by day 10. The placebo group lost strength over this same interval. In the IVIg, 11 subjects improved by the functional disability scale; none worsened. This differed (p = 0.019) from those in the placebo-treated group (two improved, two got worse, remainder unchanged). Forced vital capacity did not improve with IVIg treatment. IVIg improved ulnar motor distal latency (p = 0.005), tibial distal compound muscle amplitude (p = 0.003), and peroneal nerve conduction velocity (p = 0.03).

CONCLUSIONS

IVIg improves strength in patients with untreated CIDP by day 10 with continued benefit through day 42; more than one third improve by at least a functional grade on a disability scale. This study provides data supporting IVIg as the initial treatment for CIDP.

Mutation analysis of the cystic fibrosis and cationic trypsinogen genes in patients with alcohol-related pancreatitis

Cationic trypsinogen and cystic fibrosis mutations have been identified in pancreatitis patients, although no study has looked for mutations in both genes in the same patient. Pancreatitis can be induced by alcohol, although not all alcoholics develop pancreatitis. We hypothesize that this phenomenon is due to a genetic predisposition in persons with alcohol-related pancreatitis. We performed sequence analysis of the cationic trypsinogen-coding region in 46 alcohol-related pancreatitis patients and 16 patients with pancreatitis due to causes other than alcohol. We also screened for 40 cystic fibrosis mutations including the 5T allele. No cationic trypsinogen mutations were identified. Cystic fibrosis mutation screening identified the DeltaF508 mutation in two Caucasian alcoholic patients (P<0.025). The cystic fibrosis mutation carrier frequency in African-American alcoholic patients was 3%, which was not significantly increased compared with the normal carrier frequency. The frequency of the 5T allele was not significantly increased compared with the normal population carrier frequency in either racial group. These results may suggest a role for the cystic fibrosis gene in alcohol-related pancreatitis but indicate that cationic trypsinogen mutations are not a common predisposing risk factor for alcohol-related pancreatitis. A multicenter study is necessary to attain sufficient numbers to come to a conclusion.

Superficial peroneal nerve/peroneus brevis muscle biopsy in vasculitic neuropathy

OBJECTIVE

To determine the sensitivity and specificity of superficial peroneal nerve (SPN)/peroneus brevis muscle (PBM) biopsy in a cohort of patients with suspected peripheral nerve vasculitis.

BACKGROUND

In patients with suspected vasculitic neuropathy, combined nerve and muscle biopsies have been advocated as a way to increase the diagnostic yield, but the sensitivity and specificity of this approach have not been evaluated. Pathologic predictors of biopsy-proven peripheral nerve vasculitis have also not been analyzed in a systematic fashion.

METHODS

The clinical, laboratory, and pathologic data for all patients undergoing SPN/PBM biopsy for possible vasculitis from 1986 through 1996 were analyzed. Biopsies were classified as positive, negative, or suspicious for vasculitis. Patients were then divided into vasculitis and nonvasculitis cohorts by final clinical diagnosis.

RESULTS

Of 70 SPN/PBM biopsies, 22 (30%) showed definite vasculitis; nerve was diagnostic in 90% (n = 20) and muscle in 50% (n = 11). Nerve biopsy had a higher yield than muscle in patients with nonsystemic vasculitic neuropathy (p = 0. 0047) but not in those with systemic vasculitis. The estimated sensitivity of a positive SPN/PBM biopsy for vasculitis was 60%. Considering biopsies either positive or suspicious for vasculitis increased the sensitivity to 86% with a corresponding specificity of 85%. Pathologic features associated with necrotizing vasculitis were muscle fiber necrosis/regeneration (relative risk 18.1; 95% CI 3.4 to 96.1), predominant axonal nerve pathology (>8.8; >1.0 to 77.4), Wallerian-like degeneration (5.6; 1.4 to 21.9), and asymmetric nerve fiber loss (4.6; 1.4 to 15.9).

CONCLUSIONS

These findings establish the yield, sensitivity, and specificity of SPN/PBM biopsy for diagnosing vasculitic neuropathy and validate the use of suggestive pathologic features for diagnosing cases lacking definite necrotizing vascular changes.

Mutation analysis of the cystic fibrosis and cationic trypsinogen genes in patients with alcohol-related pancreatitis

Cationic trypsinogen and cystic fibrosis mutations have been identified in pancreatitis patients, although no study has looked for mutations in both genes in the same patient. Pancreatitis can be induced by alcohol, although not all alcoholics develop pancreatitis. We hypothesize that this phenomenon is due to a genetic predisposition in persons with alcohol-related pancreatitis. We performed sequence analysis of the cationic trypsinogen-coding region in 46 alcohol-related pancreatitis patients and 16 patients with pancreatitis due to causes other than alcohol. We also screened for 40 cystic fibrosis mutations including the 5T allele. No cationic trypsinogen mutations were identified. Cystic fibrosis mutation screening identified the DeltaF508 mutation in two Caucasian alcoholic patients (P<0.025). The cystic fibrosis mutation carrier frequency in African-American alcoholic patients was 3%, which was not significantly increased compared with the normal carrier frequency. The frequency of the 5T allele was not significantly increased compared with the normal population carrier frequency in either racial group. These results may suggest a role for the cystic fibrosis gene in alcohol-related pancreatitis but indicate that cationic trypsinogen mutations are not a common predisposing risk factor for alcohol-related pancreatitis. A multicenter study is necessary to attain sufficient numbers to come to a conclusion.

Variable expressivity of familial medullary thyroid carcinoma (FMTC) due to a RET V804M (GTG-->ATG) mutation

BACKGROUND

Multiple endocrine neoplasia type 2 (MEN 2) and familial medullary thyroid carcinoma (FMTC) are autosomal dominantly inherited cancer syndromes that predispose to C-cell hyperplasia and MTC. MEN 2A and FMTC are caused by mutations in the RET proto-oncogene.

METHODS

We used a multiplex polymerase chain reaction-based assay to screen exons 10, 11, 13, and 14 of RET for mutations in 2 families with FMTC. We correlated mutation status with calcitonin and pathologic studies to determine genotype-phenotype correlations.

RESULTS

We identified a mutation in codon 804 in exon 14 (GTG-->ATG; V804M) in both families. An 86-year-old person who was a gene carrier and other individuals over age 70 who were suspected by pedigree analysis to be gene carriers had no overt clinical evidence of MTC. Four of 21 patients who underwent a thyroidectomy also had papillary thyroid cancer. One individual in each family had metastatic MTC at age 30 and 32 years, and all 26 people having thyroidectomies had either MTC or C-cell hyperplasia, leading us to continue to recommend prophylactic thyroidectomy for all identified patients who were gene carriers.

CONCLUSIONS

Because of active MTC in younger members of these families, including metastases, we have continued to advocate thyroid surgery in mutation-positive individuals. While DNA diagnosis of gene carriers and subsequent genetic counseling was relatively straightforward, the acceptance of surgical recommendations was more difficult for some individuals. These families demonstrate that the search for RET mutations should include exons 13, 14, 15, and 16 in patients whose studies in exons 10 and 11 are negative.