Mutation of the matrix metalloproteinase 2 gene (MMP2) causes a multicentric osteolysis and arthritis syndrome.

The inherited osteolyses or 'vanishing bone' syndromes are a group of rare disorders of unknown etiology characterized by destruction and resorption of affected bones. The multicentric osteolyses are notable for interphalangeal joint erosions that mimic severe juvenile rheumatoid arthritis (OMIMs 166300, 259600, 259610 and 277950). We recently described an autosomal recessive form of multicentric osteolysis with carpal and tarsal resorption, crippling arthritic changes, marked osteoporosis, palmar and plantar subcutaneous nodules and distinctive facies in a number of consanguineous Saudi Arabian families. We localized the disease gene to 16q12-21 by using members of these families for a genome-wide search for homozygous-by-descent microsatellite markers. Haplotype analysis narrowed the critical region to a 1.2-cM region that spans the gene encoding MMP-2 (gelatinase A, collagenase type IV; (ref. 3). We detected no MMP2 enzymatic activity in the serum or fibroblasts of affected family members. We identified two family-specific homoallelic MMP2 mutations: R101H and Y244X. The nonsense mutation effects a deletion of the substrate-binding and catalytic sites and the fibronectin type II-like and hemopexin/TIMP2 binding domains. Based on molecular modeling, the missense mutation disrupts hydrogen bond formation within the highly conserved prodomain adjacent to the catalytic zinc ion.

Gaucher disease with oculomotor apraxia and cardiovascular calcification (Gaucher type IIIC).

The authors describe four siblings from consanguineous parents who presented with oculomotor deficit in early childhood characterized by impaired volitional horizontal saccades, compensatory lateral head thrust, and preservation of vertical movement. When about 10 years of age, heavily calcified aortic and mitral valves required surgery. Fibroblast beta-glucocerebrosidase activity was markedly reduced. Genotype analysis indicated that the two patients who were tested were homozygous for the D409H (1342G-->C) mutation. Relating this rare phenotype of Gaucher disease to D409H mutation will facilitate management of the disease and counseling of families.

A novel form of autosomal recessive pure hereditary spastic paraplegia maps to chromosome 13q14.

BACKGROUND: Hereditary spastic paraplegia (HSP) is a clinically and genetically heterogeneous disorder characterized by a progressive weakening and spasticity of the lower limbs. HSP is classified according to the presence or absence of accompanying neurologic problems and by the mode of inheritance. Currently, 17 loci have been linked to the various forms of HSP. OBJECTIVE: To determine the chromosomal location of a gene causing pure autosomal recessive spastic paraplegia. METHODS: Genotyping using fluorescently labeled microsatellite markers was performed on three affected individuals and three unaffected individuals from a family displaying pure autosomal recessive HSP (ARHSP) and sensorineural deafness. All family members were then included in the analysis to narrow the genetic interval. Candidate genes were screened for the presence of mutations by heteroduplex analysis. RESULTS: The paraplegic trait linked to a 1.8-Mb region of chromosome 13q14 flanked by the FLJ11712 gene and the microsatellite marker D13S270. The deafness did not link to this region and did not cosegregate with the paraplegic trait. CONCLUSION: The HSP that this family had represents a novel genetic form of pure ARHSP as no other form of HSP (autosomal dominant or recessive) has been linked to chromosome 13.

Familial crossed polysyndactyly.

We have observed a distinct form of "crossed" polysyndactyly in 6 generations of a family with 5 affected persons, all males. The polydactyly is postaxial in the hands and preaxial in the feet. Syndactyly in the hands is observed in some relatives, while syndactyly in the feet is present bilaterally in all affected relatives. This seems to be an autosomal dominant trait with male to male transmission over 3 generations by examination and an additional 3 generations by history. This form of polysyndactyly could not be readily categorized by the existing classification by Temtamy and McKusick [1978: BD OAS XIV 6:363-392]. We review and expand the present classification of polydactyly and syndactyly syndromes.

Localization of the gene for X-linked nephrogenic diabetes insipidus to Xq28.

X-linked nephrogenic diabetes insipidus (NDI) was segregating in a large Indiana family. It was tested for linkage of the NDI gene to X-chromosome molecular markers. Maximum lod scores of 3.15 and 3.01 (theta = 0) obtained for the molecular markers F8A (F8C) and DXS15 (DX13) respectively, indicate that the NDI gene is located in Xq28. A lod score of 3.61 (theta = 0) was obtained with multipoint linkage analysis of F8A and DXS15.

Segregation of the fragile X mutation from a male with a full mutation: unusual somatic instability in the FMR-1 locus.

Fragile X syndrome is associated with an unstable CGG-repeat in the FMR-1 gene. There are few reports of affected males transmitting the FMR-1 gene to offspring. We report on a family in which the propositus and his twin sister each had a full mutation with abnormal methylation. Their mother had an FMR-1 allele in the normal range and a large premutation, with normal methylation. The maternal grandmother had two normal FMR-1 alleles. The maternal grandfather had an unusual somatic FMR-1 pattern, with allele size ranging from premutation to full mutation. No allele was detectable by PCR analysis. Multiple Southern blot analyses identified a hybridization pattern that originated at a distinct premutation band and extended into the full mutation range. Methylation studies revealed a mosaic pattern with both unmethylated premutations and methylated full mutations. This individual declined formal evaluation but did not finish high school and has difficulty in reading and writing. The size of the premutation FMR-1 allele passed to his daughter is larger than his most prominent premutation allele. This is most likely due to gonadal mosaicism similar to that in his peripheral lymphocytes. Alternatively, this expansion event may have occurred during his daughter's early embryonic development and this large premutation allele is mitotically unstable. This pattern of FMR-1 alleles in a presumably mildly affected male is highly unusual. These findings are consistent with the absence of transmission of a full fragile X mutation through an expressing male. Studies of tissue specific FMR-1 allele expansion and FMR-1 protein expression on this individual should help to determine the correlation of the molecular findings with the phenotypic effects.

Sanjad-Sakati and autosomal recessive Kenny-Caffey syndromes are allelic: evidence for an ancestral founder mutation and locus refinement.

The Sanjad-Sakati syndrome (SSS; MIM241410), an autosomal recessive trait characterized by congenital hypoparathyroidism, growth and mental retardation, seizures, and a characteristic physiognomy, was recently linked to chromosome area 1q42-q43. SSS resembles the autosomal recessive form of Kenny-Caffey syndrome (KCS; MIM244460), with similar manifestations but lacking osteosclerosis. Since KCS was recently linked to the region 1q42-q43, the possibility that this disorder is allelic with SSS was considered. Eight Sanjad-Sakati families from Saudi Arabia were genotyped with polymorphic short tandem repeat markers from the SSS/KCS critical region. A maximum multipoint LOD score of 14.32 was obtained at marker D1S2649, confirming linkage of SSS to the same region as autosomal recessive KCS. Haplotype analysis refined the critical region to 2.6 cM and identified a rare haplotype present in all the SSS disease alleles, indicative of a common founder. In addition to the assignment of the Saudi SSS and Kuwaiti KCS syndromes to overlapping genetic intervals, comparison of the haplotypes unexpectedly demonstrated that the diseases shared an identical haplotype. This finding, combined with the clinical similarity between the two syndromes, suggests that the two conditions are not only allelic but are also caused by the same ancestral mutation.

Cellular distribution of the RNA transcripts of a newly discovered gene in the brain of normal, weaver, Purkinje cell degeneration and reeler mutant mice as evidenced by in situ hybridization histochemistry.

After we identified several novel cDNAs by screening a neonatal (P1) heterozygous weaver (wv/+) cerebellar cDNA expression library with a rabbit anti-mouse granule cell antiserum, we characterized and sequenced one cDNA, GCAP-8 (standing for granule cell antiserum positive, clone number 8). In this study we examined its expression and cellular distribution in adult cerebellar mutant mice as evidenced by in situ hybridization histochemistry. In wild-type (+/+) brain, strong hybridization signal is seen in cerebellum, hippocampus, substantia nigra (SN), and cerebral cortex; in the cerebellum, hybridization signal is seen in granule cells, Purkinje cells, and in cells of the deep cerebellar nuclei. In the granuloprival weaver (wv/wv) cerebellum, hybridization signal is seen mainly in Purkinje cells. GCAP-8 expression is reduced in wv/wv SN pars compacta, which is known to lose dopamine (DA) neurons. In Purkinje cell degeneration (pcd/pcd) mutants, granule cells show hybridization signal, but overall expression is decreased owing to the absence of Purkinje cells. In reeler (rl/rl) cerebellum, the strongest hybridization signal is found in a thin granule cell layer without the typical foliation pattern, while grain clusters representing ectopic Purkinje cells are observed in the subcortical white matter and the area of the deep cerebellar nuclei. GCAP-8 expression in the reeler hippocampus and cerebral cortex shows a mixing of layers, which is known to be an aspect of the histological phenotype of this mutant.(ABSTRACT TRUNCATED AT 250 WORDS)

Novel cDNA clones obtained by antibody screening of a mouse cerebellar cDNA expression library.

In order to obtain cDNAs of genes that are expressed in cerebellar granule cells (GC), an antiserum was raised against GC isolated from mouse cerebella. Western blot analysis demonstrated that antibodies against multiple proteins were present and immunohistochemical analysis showed that at least some of these proteins were localized to cerebellar GC. The antiserum was used to screen an expression library derived from mouse cerebellar cDNA. Twenty-two granule cell antibody-positive (GCAP) clones were obtained. Of these, eight represented genes previously described and 14 were novel clones (not found in the GenBank database). In situ hybridization histochemistry showed that eight of the novel clones had moderate to strong expression in cerebellar GC and some of these clones were expressed also in the hippocampal formation. One such clone, GCAP-7, appears to represent a single-copy gene and the entire cDNA insert (2,688 bp) has been sequenced. The clone appears to consist primarily of the 3' untranslated portion, including a poly(A) tail and polyadenylation signals, of a 5 kb transcript. The GCAP clones should be useful for future studies of molecular biology of GC in normal individuals and in inherited neurologic disease with GC degeneration.

Molecular characterization of a novel cDNA from murine cerebellum, developmental expression, and distribution in brain.

Several novel cDNA clones were previously identified by immunoscreening a cerebellar cDNA expression library derived from heterozygous weaver (wu/+) mice at postnatal day one (P1) with an antigranule cell antiserum. One cDNA, GCAP-8 (granule cell antiserum-positive clone 8) has been further characterized. The 1.1 kb insert is a partial cDNA containing a segment near the 3' end of the full-length cDNA. The 5' end of the GCAP-8 cDNA contains a 259 nucleotide open reading frame (ORF) coding for the last 85 amino acids of the carboxy terminus of the encoded protein. The encoded polypeptide contains two highly hydrophobic segments interrupted by a basic stretch. The carboxy terminus of this protein is cysteine-rich, with 10 cysteine residues among the 85 amino acids. The GCAP-8 cDNA probably represents a single-copy gene. The GCAP-8 gene, designated Gcap1, was mapped to the distal region of mouse chromosome 5 by the analyses of two multilocus crosses. The distribution of the GCAP-8 mRNA in mouse brain was studied by in situ hybridization histochemistry. In the adult mouse brain, strong hybridization was detected in cerebellum, hippocampus, substantia nigra (SN), and cerebral cortex. In mouse cerebellum, hybridization was detected in granule cells, Purkinje cells, and in cells of the deep cerebellar nuclei (DCN). In human cerebellum, hybridization was detected in the granule cell layer. In the mouse, GCAP-8 is expressed at least as early as embryonic day 14 (E14) in the central nervous system (CNS).

Clinical value of direct DNA analysis of the RET proto-oncogene in families with multiple endocrine neoplasia type 2A.

BACKGROUND: The multiple endocrine neoplasia type 2A gene is the RET proto-oncogene located on the long arm of chromosome 10, and many mutations within this gene have been reported. METHODS: Peripheral blood DNA was analyzed from 95 members of twelve families with multiple endocrine neoplasia type 2A and known mutations in codon 634 (of exon 11) of the RET proto-oncogene. This region was amplified by the polymerase chain reaction, followed by digestion with Cfo I, which detects restriction sites created by the most common TGC- > CGC mutation and by a TGC- > TGG mutation or with Rsa I, which detects a restriction site created by a TGC- > TAC mutation. RESULTS: Diagnoses were confirmed in 39 patients; 15 of 56 at-risk persons were gene carriers and 41 were noncarriers. The noncarriers included seven persons who had previously undergone thyroidectomies for suspected C-cell hyperplasia but were negative for the RET mutation present in affected members of their families. CONCLUSIONS: Identification of the specific gene alterations within families permits direct DNA diagnosis of at-risk family members. The 41 noncarriers will not require further testing nor need to be concerned about transmitting multiple endocrine neoplasia type 2A to their descendants. The normal DNA findings in seven of these persons emphasize the importance of DNA studies in patients with C-cell hyperplasia but no medullary thyroid cancer at operation.

Sequences from the aspergillopepsin PEP gene of Aspergillus fumigatus: evidence on their use in selective PCR identification of Aspergillus species in infected clinical samples.

In immunodeficient patients, Aspergillus species emerge as circumstantial pathogens. Aspergillus fumigatus is a distant first among the pathogenic aspergilli, which cause deep-seated mycoses. Sequences of the pep gene of A. fumigatus as potential PCR primers, which have not been tested before, were used to identify this species and if possible, differentiate it from other, co-identified, clinically important species of the genus. We present results of the three most promising primer pairs, pep-1/pep-22, pep-15/pep-22 and pep-21/pep32. The second pair was of better specificity when tested with DNA extracted from pure cultures of a multitude of aspergilli, whereas the first co-amplified four clinically significant Aspergillus species. The compatibility of the PCR method with the CTAB DNA extraction protocol varied according to the biological fluid tested and the primer pair used. The first two pairs showed moderate adaptability to the different commercial DNA extraction kits, which were tested in whole blood, spiked with Aspergillus fumigatus hyphae and conidia - as were all the biological fluids used. Restriction of the amplification products with MspI produced distinct patterns for different Aspergillus spp. This approach, as a potential diagnostic tool, seems reliable and sensitive due to its flexibility, speed, low cost, ease of application and selectable breadth of detection.

Identification of medically significant fungal genera by polymerase chain reaction followed by restriction enzyme analysis.

Rapid non-culture-dependent assays for identification of fungi quicken diagnosis and prompt treatment of invasive fungal disease. Fungal DNA extracts from pure cultures of the most frequently isolated fungal pathogens belonging to the Genera Aspergillus, Candida and Cryptococcus along with less common pathogenic Genera were amplified with the general fungal primer pair internal transcribed spacer-1/4. Subsequently, the amplicon was digested with the restriction endonucleases MspI, HaeIII, HinfI and EcoRI in order to generate genus- or species-specific patterns for identification of the fungus. HinfI produced indistinguishable fingerprints for all Aspergillus species tested. MspI produced species-specific patterns for: Cryptococcus neoformans, Cryptococcus non-neoformans, Candida albicans and Candida tropicalis. EcoRI succeeded in differentiating penicillia from aspergilli and cryptococci from Candida spp. It is concluded that this procedure can differentiate genera and occasionally species of medically important fungi and that following the necessary validation experiments, it can be used directly on clinical samples to assist prompt diagnosis of systemic fungal infections.

Relationship of familial prominent corneal nerves and lesions of the tongue resembling neuromas to multiple endocrine neoplasia type 2B.

PURPOSE: We studied a two-generation family with an inherited syndrome of prominent corneal nerves and lesions of the tongue resembling neuromas without the characteristic neoplasms of the multiple endocrine neoplasia type 2B syndrome. Several different point mutations in the RET proto-oncogene on chromosome 10 have been associated with the multiple endocrine neoplasia type 2 syndromes. Molecular genetic studies of families with partial phenotypic expression of these syndromes may aid in further understanding the origin of the variety of clinical manifestations observed in multiple endocrine neoplasia type 2. METHODS: A family consisting of an 8-year-old male proband, his 10-year-old sister, and 40-year-old mother was identified as having prominent corneal nerves and lesions of the tongue resembling neuromas. Pentagastrin-stimulated serum calcitonin levels were measured in the mother and sister. Molecular genetic studies were performed on all three affected members, to look for the specific point mutation seen in over 95% of patients with multiple endocrine neoplasia type 2B. RESULTS: Serum calcitonin levels were normal, indicating no C-cell hyperplasia or medullary thyroid carcinoma. Molecular genetic studies on these individuals did not disclose the specific point mutation seen in multiple endocrine neoplasia type 2B. CONCLUSIONS: This family demonstrates some of the phenotypic features of the multiple endocrine neoplasia type 2B syndrome without the characteristic neoplasms or the mutation in the RET proto-oncogene associated with multiple endocrine neoplasia type 2B. Their physical findings may be caused by genetic alterations within the RET proto-oncogene on chromosome 10 at yet undetermined sites.

A novel autosomal recessive "Huntington's disease-like" neurodegenerative disorder in a Saudi family.

Full text is available as a scanned copy of the original print version.

Genomics DNA profiling in elite professional soccer players: a pilot study.

Functional variants in exonic regions have been associated with development of cardiovascular disease, diabetes and cancer. Athletic performance can be considered a multi-factorial complex phenotype. Genomic DNA was extracted from buccal swabs of seven soccer players from the Fulham football team. Single nucleotide polymorphism (SNPs) genotyping was undertaken. To achieve optimal athletic performance, predictive genomics DNA profiling for sports performance can be used to aid in sport selection and elaboration of personalized training and nutrition programs. Predictive DNA profiling may be able to detect athletes with potential or frank injuries, or screening and selection of future athletes, and can help them to maximize utilization of their potential and improve performance in sports. The aim of this study is to provide a wide scenario of specific genomic variants that an athlete carries, to implement which measures should be taken to maximize the athlete's potential.

Novel Twinkle gene mutation in autosomal dominant progressive external ophthalmoplegia and multisystem failure.

A Saudi Arabian family presented with adult onset autosomal dominant progressive external ophthalmoplegia (adPEO) complicated by late onset reversible failure of the CNS, respiratory, hepatic, and endocrine systems. Clinical findings were suggestive of mitochondrial dysfunction and multiple mitochondrial DNA deletions were demonstrated on long range and real time polymerase chain reaction assays but not on Southern blotting. The disorder is caused by a novel heterozygous PEO1 mutation predicting a Leu360Gly substitution in the twinkle protein. The peculiar clinical presentation expands the variable phenotype observed in adPEO and Twinkle gene mutations.

An augmented auditory feedback device.

An augmented auditory feedback device is described. The device can be easily and economically constructed and implemented during a patient's physical rehabilitation. The rationale is to provide an external source of information to the user in order to correct errors during weight-bearing activities. Possible applications of the augmented auditory feedback device include increasing symmetry and weight distribution during sitting, standing, and gait. Instructions regarding its construction are provided, and a case study using the device is presented. Improved midline alignment and weight distribution in sitting for a 2-hour duration was achieved by a stroke patient using the augmented auditory feedback device in conjunction with physical therapy.

Diagnosis of multiple endocrine neoplasia [MEN] 2A, 2B and familial medullary thyroid cancer [FMTC] by multiplex PCR and heteroduplex analyses of RET proto-oncogene mutations.

Multiple endocrine neoplasia type 2 [MEN 2] is an autosomal dominant cancer syndrome with two subtypes, 2A and 2B. MEN 2A and medullary thyroid cancer [MTC] are caused by > 25 different point mutations in exons 10, 11, and 13 of the RET proto-oncogene, whereas MEN 2B is caused by a single exon 16-point mutation. Various molecular methods have been used to identify the different mutations, including DNA sequencing, restriction enzymatic analyses, chemical cleavage mismatch, Single Stranded Conformational Polymorphism [SSCP], and Denaturing Gradient Gel Electrophoresis [DGGE]. These techniques, although useful and accurate, are labor intensive and some involve the use of radioactivity. We have developed a multiplex PCR assay simultaneously to amplify exons 10, 11, and 13 of the RET proto-oncogene. The multiplex PCR product is then analyzed on a modified Mutation Detection Enhancement [MDE] matrix for heteroduplex identification and visualized with ethidium bromide. Distinct heteroduplexes were detected for each known RET proto-oncogene mutation available in our laboratory (nine in exon 10, five in exon 11, one in exon 13, and the single exon 16 mutation). Presymptomatic DNA diagnosis of MEN 2 is essential since pentagastrin-stimulated calcitonin studies can occasionally produce false positive results and lead to unnecessary thyroidectomies. Prophylactic thyroidectomy is recommended by age 5 or 6 once a mutation is identified in a patient, since penetrance is very high. MDE heteroduplex detection provides a quick, efficient, and inexpensive method of screening for RET mutations in MTC patients with unknown mutations, or for presymptomatic diagnosis in individuals at risk for inheriting a known RET mutation. Confirmation of the specific mutation can be achieved by restriction enzymatic digestion (if feasible) or by DNA sequencing.

Mutation of p16, p21 or cyclin dependent kinase 4 is rare in acute lymphoblastic leukaemia.

Homozygous deletion of the p16 tumour suppressor gene (at frequencies ranging from 14% to 29%) have been implicated in the pathogenesis of acute lymphoblastic leukaemia (ALL) by several studies. We investigated the prevalence of this deletion in a group of 46 Arab patients with common ALL. Deletion of p16 was assessed in a multiplex PCR which amplified a 405 bp fragment from exon 2 of the p16 gene, and a 242 bp fragment of the ApoE lipoprotein gene which served as an internal control. Homozygous deletion of p16 in tumour cells could be readily detected in samples containing >75% blasts. Surprisingly, none of the cases in our study showed homozygous deletion of the p16 gene. We also investigated the possibility of other genetic alterations in the p16 gene or mutation in the p21 and CDK4 (not previously reported in ALL) genes which are part of the same signal transduction pathway. A heterozygous G --> A transition at nucleotide position 273 of the p16 gene was present in one patient, but did not result in an amino acid change. A C --> A transversion at codon 88 of the p21 gene, which results in replacement of a phenylalanine with a leucine at position 63, was detected in one patient. In another patient a G --> C transversion in exon 2 at codon 82 (5'-untranslated region of the CDK4 gene) was detected. Results of this study showed mutation of p16, p21 or CDK4 to be rare events in Arab ALL patients.