Ectopic expression of NnPER1, a Nelumbo nucifera 1-cysteine peroxiredoxin antioxidant, enhances seed longevity and stress tolerance in Arabidopsis.

Seed longevity, the maintenance of viability during storage, is a major factor for conservation of genetic resources and biodiversity. Seed longevity is an important trait of agriculture crop and is impaired by reactive oxygen species (ROS) during seed desiccation, storage and germination (C. R. Biol., 331, 2008 and 796). Seeds possess a wide range of systems (protection, detoxification, repair) allowing them to survive during storage and to preserve a high germination ability. In many plants, 1-cys peroxiredoxin (1-Cys Prx, also named PER1) is a seed-specific antioxidant which eliminates ROS with cysteine residues. Here we identified and characterized a seed-specific PER1 protein from seeds of sacred lotus (Nelumbo nucifera Gaertn.). Purified NnPER1 protein protects DNA against the cleavage by ROS in the mixed-function oxidation system. The transcription and protein accumulation of NnPER1 increased during seed desiccation and imbibition and under abiotic stress treatment. Ectopic expression of NnPER1 in Arabidopsis enhanced the seed germination ability after controlled deterioration treatment (CDT), indicating that NnPER1 improves seed longevity of transgenic plants. Consistent with the function of NnPER1 on detoxifying ROS, we found that the level of ROS release and lipid peroxidation was strikingly lower in transgenic seeds compared to wild-type with or without CDT. Furthermore, transgenic Arabidopsis seeds ectopic-expressing NnPER1 displayed enhanced tolerance to high temperature and abscisic acid (ABA), indicating that NnPER1 may participate in the thermotolerance and ABA signaling pathway.

[Association study between candidate genes on transforming growth factor-ß signaling pathway and the risk of non-syndromic cleft lip with or without cleft palate in Chinese populations].

OBJECTIVE: To explore the association between 10 candidate genes on transforming growth factor-ß (TGFB) signaling pathway and non-syndromic cleft lip with or without cleft palate (NSCL/P) among Chinese populations, and to study the gene-environment interaction. METHODS: A total of 806 Chinese Han NSCL/P trios were ascertained from an international consortium, which conducted a genome-wide association study using a case-parent trio design to investigate the genes affecting risk to NSCL/P. The transmission disequilibrium test (TDT) was used to test for effects of 343 single nucleotide polymorphisms (SNPs) in 10 genes on TGFB signaling pathway including DCN, TGFB1, TGFB2, TGFB3, TGFBR1, TGFBR2, BAMBI, SMAD2, SMAD3 and SMAD4. The conditional regression models were used to test for gene-environment interaction. RESULTS: For TDT, although 19 SNPs showed nominal significant association with NSCL/P, no significant evidence of association was seen for all SNPs in 806 NSCL/P trios after Bonferroni correction. The interactions between genes and maternal smoking, environmental tobacco smoke, alcohol consumption and multi-vitamin supplementation during pregnancy did not attain statistical significance after correction for multiple comparisons. CONCLUSION: No evidence for SNP effect of genes on TGFB signaling pathway and significant gene-environment interaction was seen in our data.

[Association study for gene polymorphism of folic acid/homocysteine metabolic pathway and nonsyndromic cleft lip with or without cleft palate in Chinese populations].

OBJECTIVE: To explore the association between 18 candidate genes encoding enzymes on the folate/homocysteine metabolism pathway and non-syndromic cleft lip with or without cleft palate (NSCL/P) in Chinese populations. METHODS: A total of 806 NSCL/P trios were drawn by an international consortium, which conducted a genome-wide association study using a case-parent trio design to investigate genes affecting risks to NSCL/P. The transmission disequilibrium test (TDT) was used for deviation from Mendelian expectations for 257 SNPs in 18 folate/homocysteine metabolism-related genes. The interactions between markers in these gene and environmental risk factors were also tested using conditional Logistic regressions. RESULTS: Although four SNPs (rs6428977, rs12060264, rs7730643 and rs4920037) showed nominal significant association with NSCL/P in the TDT on 806 NSCL/P trios (P<0.05), no significant evidence of linkage and association remained in all the SNPs after Bonferroni correction. Similar tests for interactions between genes and maternal smoking, environmental tobacco smoke, alcohol consumption and multi-vitamin supplementation during pregnancy did not attain statistical significance after correction for multiple comparisons. CONCLUSION: Folate/homocysteine metabolism-related genes could not influence the risk of NSCL/P.

EDM1: a novel point mutation in cartilage oligomeric matrix protein gene in a Chinese family with multiple epiphyseal dysplasia.

BACKGROUND: Multiple epiphysis dysplasia (MED) is a common skeletal dysplasia with a significant locus heterogeneity. In the majority of clinically defined cases, mutations have been identified in the gene encoding cartilage algometric matrix protein (COMP). METHODS: Five patients were included in the study. Linkage analysis and mutation analysis of the COMP gene were conducted in the patients and their family members. RESULTS: We have identified a novel mutation in axon 14 of COMP gene in the family. CONCLUSIONS: This mutation produced a severe MED phenotype with marked short stature, early onset osteoarthritis, and remarkable radiographic changes. Our results extended the range of disease-causing mutations in COMP gene and contributed more information about relationship between mutations and phenotype.

[Clinical characterization and mutation identification for multiple sulfatase deficiency patients in China].

OBJECTIVE: Multiple sulfatase deficiency is a rare autosomal recessively inherited lysosomal storage disorder characterized by the accumulation of sulfated lipids and acid mucopolysaccharides. The aim of this study was to explore the clinical manifestations, enzyme activities and SUMF1 gene mutations in two Chinese patients with multiple sulfatase deficiency. METHOD: One boy and one girl from two families were studied. Both patients presented with mental retardation, mild coarse facial features, a neurodegenerative course of disease with loss of sensory and motor function after 2 years of age, ichthyosis and skeletal abnormalities (kyphosis or/and scoliosis). Clinical characteristics indicate multiple sulfatase deficiency.Sulfatases activities in blood leucocytes, plasma or cultured fibroblast of the patients were measured.Genomic DNAs were extracted from peripheral blood leukocytes from the patients and their parents. All SUMF1 gene exons and intron-exon boundaries were amplified by PCR and subjected for direct sequencing. RESULT: In case 1, five sulfatases activities of blood leucocytes and four sulfatases of cultured skin-fibroblasts were analyzed.In case 2, three sulfatases activities of blood leucocytes were tested.Significantly decreased sulfatases activities confirmed the diagnosis of multiple sulfatase deficiency.On SUMF1 gene, c.793_794 insATG (p. P265X)/ c.1045C>T (p.R349W) in case 1 and c.451A>G (p.K151E)/ c.1046G>C (p.R349Q) in case 2 were detected, respectively. Three novel mutations c.793_794insAGT, c.1046G>C and c.451A>G were identified. CONCLUSIONS: Multiple sulfatase deficiency usually results in multi-organ damage, especially neurologic, skeletal and skin.Sulfatases assay and SUMF1 gene analysis are necessary for the diagnosis. Two Chinese cases with multiple sulfatase deficiency were firstly reported. Three novel mutations were found.It should be considered that the mutation profile of SUMF1 gene in Chinese patients is different from other populations.

[Analysis of ITD characteristics in acute myeloid leukemia patients with FLT3-ITD positive].

The aim of this study was to analyze the FMS-like tyrosine kinase 3 internal tandem duplication (FLT3-ITD) allelic ratios (AR), number of ITD, ITD length and positions of ITD insertions in de novo acute myeloid leukemia (AML) patients with FLT3-ITD positive, and the relationship between mutant level and therapeutic efficacy. Genomic DNA was amplified by PCR, capillary electrophoresis was used to detect the ITD characteristics in 31 de novo AML patients, and DNA sequences analysis of FLT3-ITD(+) were performed in 13 patients. The results showed that the ratios of mutant to wild type FLT3 allele ranged from 0.01 to 2.8; 28 patients (90.32%) had a single ITD, the remaining 3 patients had more than one ITD; the ITD length ranged from 3 to 144 bp in all FLT3-ITD(+) patients. 13 sequence-analyzed patients, 4 patients were of pure duplications, and 2 patients had foreign bases inserted, and the other 7 patients were partial duplications. The ITD occurred in the regions from p.E573 to p.P606 of the FLT3 protein, with the majority clustered in a stretch between p.F590 and p.R595. The complete remission (CR) rate in AR < 0.5 patients (43.75%) were more prevalent as compared with AR ≥ 0.5 patients (16.67%) (p > 0.05). It is concluded that the ITD length and AR are vary widely. Some of the insertions are foreign bases, and all of the 13 sequences-analyzed ITD were concentrated on the juxtamembrane domain. The CR rate in patients of AR < 0.5 had no statistical significance compared with patients of AR ≥ 0.5.

[Two novel EIF2AK3 mutations in a Chinese boy with Wolcott-Rallison syndrome].

OBJECTIVE: Wolcott-Rallison syndrome (WRS) is a rare autosomal recessive disorder characterized by the association of permanent neonatal or early-infancy insulin-dependent diabetes, multiple epiphyseal dysplasia and growth retardation, and other variable multisystem clinical manifestations. Here we describe a Chinese boy affected by WRS. Genetic testing of his EIF2AK3 gene was performed in order to elucidate molecular variations and subsequently to provide credible genetic counseling for prenatal diagnosis in his family. METHOD: Based on analysis of a nine-year-old boy's clinical symptoms associated with biochemical examination and imaging, the diagnosis of WRS was therefore made. Genomic DNAs were extracted from peripheral blood leukocytes from the boy and his parents with their informed consent for genetic studies. All EIF2AK3 exons and intron-exon boundaries were amplified by Touch-down polymerase chain reaction (Touch-down PCR) and sequenced. RESULT: Direct sequencing of PCR products revealed the presence of a heterozygous T insertion (c.1408_1409insT) in exon 8 of the EIF2AK3 gene leading to frameshifting and termination, and another heterozygous T to A exchange (c.1596T > A) in exon 9 of the EIF2AK3 gene resulting in nonsense C532X mutation. CONCLUSION: Combining mutation screening of EIF2AK3 gene with clinical manifestations and effective examination may provide a reliable diagnostic method for patients. In this research, two novel mutations identified in the Chinese boy locate in the catalytic domain of the EIF2AK3 gene, disrupting the ability of autophosphorylation, leading to the truncated proteins that are unable to phosphorylate the natural substrate, which are responsible for the phenotype of Wolcott-Rallison syndrome.

[FMS-like tyrosine kinase 3 gene mutation in acute myeloid leukemia detected by denaturing PAGE and its clinical significance].

The aim of this study was to analyze the frequency of flt3 length mutation (flt3-LM) in de novo acute myeloid leukemia patients and the relationship between flt3-LM and chromosome alterations, FAB subgroups, as well as efficiency of therapy. Genomic DNA was amplified by PCR; 2% agarose gel or 8% denaturing PAGE were used to detect the length mutation of flt3 gene in 99 de novo acute myeloid leukemia patients; karyotyping in 72 AML patients was performed by G banding technique. The results showed that the flt3-LM was detected in 20.2% (20/99) patients by agarose gel electrophoresis, and in 29.9% (29/99) by denaturing PAGE. The flt3-LM was not detected in M(0) (only one patient was available), but flt3-LM occurrence in AML subtypes was as follow: in M(2) (9/30), M(3) (6/27), M(4) (4/14), M(5) (7/19), M(6) (3/8) respectively. flt3-LM in patients with normal karyotypes (39.13%) was more prevalent as compared with patients of abnormal karyotype (24.49%), but there was no statistical difference (p > 0.05). The complete remission (CR) rate in flt3-LM positive patients (36.36%) was lower than that in flt3-LM negative patients (62.75%) in the 73 patients (p < 0.05) whose karyotypic detection was performed. The distributions of flt3-LM were observed in 8 out of 40 CR patients, 8 out of 21 PR patients, and 6 out of 12 NR patients. It is concluded that the denaturing PAGE is more sensitive and reliable to detect the flt3-LM. The flt3 mutation represents a common genetic abnormality in AML patients, and the flt3-LM is associated with lower CR rate.

[Mutation analysis of PTPN11 gene in Noonan syndrome].

OBJECTIVE: To investigate the mutations in protein tyrosine phosphatase, nonreceptor-type 11 (PTPN11) gene in patients with Noonan syndrome (NS). METHODS: Three sporadic patients with NS were studied. Genomic DNAs were extracted from peripheral blood leukocytes. All 15 coding exons and their flanking intronic boundaries of the PTPN11 gene were amplified by polymerase chain reaction and followed by direct sequencing. DNAs from parents were sequenced in the corresponding region when the mutation was detected in their affected child. The identified mutation was screened in 100 healthy individuals for exclusion of polymorphism by restriction endonuclease digestion of the PCR products. Protein conservation analysis was performed among 10 species using an online ClustalW tool. RESULTS: Direct DNA sequence analysis identified a heterozygous 181G to A change in exon 3 of the PTPN11 gene in one patient, which resulted in the substitution of an aspartic acid residue by an asparagine at codon 61. The mutation was absent in his parents and 100 controls, and is located in a highly conserved amino acid site. No mutation in the coding region of PTPN11 gene was observed in the other two patients. CONCLUSION: The p.D61N mutation was reported previously in Caucasians and is a de-novo mutation in this patient. Our study further confirmed that the p.D61N is a pathogenic mutation for NS and consistent with the clinical diagnosis. Additional genes may be involved in the other two patients with NS, indicating high genetic heterogeneity of this disease.

Genetic analysis and serum level of cartilage oligomeric matrix protein in patients with pseudoachondroplasia.

BACKGROUND: Pseudoachondroplasia (PSACH) is an autosomal-dominant osteochondrodysplasia due to mutations in the gene encoding cartilage oligomeric matrix protein (COMP). Clinical diagnosis of PSACH is based primarily on family history, physical examination, and radiographic evaluation. There is evidence that decreased serum COMP concentration may serve as a diagnostic marker in PSACH. Here, we investigated the role of this gene and the serum COMP concentration in Chinese patients with PSACH. METHODS: A family with three patients and a sporadic case were recruited. Genomic and phenotypic data were recorded. The diagnosis of PSACH was made on the base of clinical evaluation. The genomic DNA was extracted from peripheral blood leukocytes. The 8-19 exons and flanking intron-exon boundary sequences of COMP were amplified by polymerase chain reaction (PCR) and screened for mutation by direct DNA sequencing. Serum COMP concentrations of 4 patients and age-compatible control group of 20 unrelated healthy subjects were analyzed on the basis of an ELISA Kit for human cartilage oligomeric matrix protein. RESULTS: A deletion (c.1447-1455del) was identified in exon 13 in the sporadic case. The mean serum COMP concentrations of four patients (3.12+/-2.28) were significantly lower than those of control group (10.86+/-2.21, P<0.05). There was no overlap in the distribution of serum COMP concentration between PSACH patients and controls. CONCLUSIONS: Mutations in COMP gene are responsible for the PSACH. Serum COMP concentration may be suggested as an additional diagnostic marker to aid clinical findings in suspected cases of PSACH.

[Novel CHST6 compound heterozygous mutations cause macular corneal dystrophy in a Chinese family].

OBJECTIVE: The aim of this study was to identify mutations of CHST6 gene in a Chinese family with macular corneal dystrophy (MCD) and to investigate the histopathological changes of MCD. METHODS: Corneal button of the proband was obtained from penetrating keratoplasty for the treatment of severe corneal dystrophy. The sections and ultrathin sections of this specimen were examined under light microscope and transmission electron microscope (TEM). Genomic DNA was extracted from leukocytes in peripheral blood from the family members. The coding region of CHST6 was amplified by polymerase chain reaction (PCR). The PCR products were analyzed by direct sequencing and restriction enzyme digestion. RESULTS: Histochemical study revealed positive results of colloidal iron stain. TEM revealed enlargement of smooth endoplasmic reticulum and the presence of intracytoplasmic vacuoles. Two mutations, Q298X Y358H, were identified in exon 3 of CHST6. Three patients were compound heterozygotes of these two mutations. The C892T transversion occurred at codon 298 turned the codon of glutamine to a stop codon; the T1072C transversion occurred at codon 358 caused a missense mutation, tyrosine to histidine. All six unaffected family members were heterozygotes. These two mutations were not detected in any of the 100 control subjects. CONCLUSIONS: The novel compound heterozygous mutation results in loss of CHST6 function and causes the occurrence of MCD. This is the first report of this gene mutation.

[Clinical manifestations and mutation study in 16 Chinese patients with Fabry disease].

OBJECTIVE: To investigate the clinical manifestations and to characterize mutations of the GLA gene in Chinese patients with Fabry disease so to enhance the diagnosis of Fabry disease. METHODS: Sixteen Chinese affected males (from 16 unrelated families) with the classic phenotype of Fabry disease were investigated. The patients were diagnosed by a deficiency of alpha-galactosidase A (alpha-Gal A) activity. All seven exons and the neighboring intronic sequences of GLA gene were analyzed by PCR amplification and automated sequencing. RESULTS: A total of 14 mutations were identified including 12 single-base substitutions (11 missense and 1 nonsense mutations), 1 small deletion and 1 splicing mutation. Eight novel mutations (c.119 C > A, c.275 A > T, c.520T > C, c.547G > C, c.647A > G, c.929T > G, c.1045T > A, IVS1-1G > A) were identified. The novel mutations were not tested by RFLP on 100 GLA alleles in Chinese population, and were highly conservative in mammalian species. CONCLUSION: Fabry disease is often misdiagnosed in China. There is no hot spot for mutations in Chinese patients. GLA gene mutation analysis is a reliable method to diagnosis for Fabry disease.

[Detection of microdeletion in Williams syndrome by multiplex ligation-dependent probe amplification].

OBJECTIVE: To establish a method of multiplex ligation-dependent probe amplification (MLPA) for clinical screening of Williams syndrome (WS) and for routine use in WS diagnosis. METHODS: Probes for MLPA were designed according to the frequent deletion regions, and used to screen the two patients suspected with Williams syndrome, and the density of the bands were analyzed with software. Linkage analysis using polymorphic markers was performed to confirm the positive result of MLPA. RESULTS: The MLPA data indicated that the two children had possible microdeletions in the WS critical region. The deletions were confirmed and both were maternal origin by polymorphism analysis. CONCLUSION: MLPA is a quick and convenient method for detecting deletion or duplication mutations. It can provide reliable and helpful information for clinical diagnose of Williams syndrome.

[Mutation analysis of the PAH gene in patients with phenylketonuria in Gansu province].

OBJECTIVE: To characterize the mutations of the phenylalanine hydroxylase (PAH) gene in patients with phenylketonuria in Gansu province. METHODS: Mutations of the PAH gene were detected in exons 3, 5, 6, 7, 11 and 12 with flaking introns of PAH gene by PCR and DNA sequencing. RESULTS: Mutations were identified in 45/58 alleles (detection rate: 96.4%), in total of 18 variants. Among them IVS12+5G>C was a novel mutation. The most frequent mutations were R243Q (22.7%), V399V (12.1%), EX6-96A>G (5.2%), R413P (5.2%) and IVS4-1G>A (5.2%), followed by Y356X (3.4%), R111X (3.4%) and INS7+2T>A (3.4%). CONCLUSION: The mutations of the phenylalanine hydroxylase gene in patients with phenylketonuria in Gansu province were similar to that in other areas of China, with obvious difference in mutation rate of some mutations.

[Gene mutation analysis of a collodion baby].

OBJECTIVE: To determine the mutations pattern of the genes of a collodion baby. METHODS: Collodion baby is a genetic heterogeneous disease caused by mutations of several genes. Since the most common mutations were observed in TGM1 gene, this gene was chosen for mutation screening. The screening was carried out by PCR and direct sequencing. The allele specific primers were designed for a missense mutation and allele-specific (AS) PCR was carried out in 50 normal individuals for population study. RESULTS: Three novel alterations were detected in TGM1 gene of the proband, a missense mutation c.463C > T (p.Arg155Trp) in exon 3, a nonsense mutation c.578G > A (p.Trp193X) in exon 4, and a single nucleotide deletion (c.694delG) also in exon 4 of TGM1 gene. This infant's father was heterozygote of c.694delG mutation, while his mother carried the two mutations (c.463C > T and c.578G > A) on the same chromosome. The missense mutation was not detected in his father and in any of the control individuals by AS-PCR. CONCLUSION: Three novel mutations were identified in TGM1 gene in a Chinese collodion baby. A double mutation (c.463C > T and c.578G > A) located on the maternal allele while the c.694delG deletion on the paternal allele.

Gene mapping of autosomal dominant retinitis pigmentosa in a Chinese family.

BACKGROUND: The autosomal dominant form of retinitis pigmentosa (ADRP) can be caused by mutations in 14 genes and further loci remains to be identified. This study was intended to identify mutations in a Chinese pedigree with ADRP. METHODS: A large Chinese family with retinitis pigmentosa was collected. The genetic analysis of the family suggested an autosomal dominant pattern. Microsatellite (STR) markers tightly linked to genes known to be responsible for ADRP were selected for linkage analysis. Exons along with adjacent splice junctions of PRPF31 were amplified by polymerase chain reaction (PCR) and screened by direct sequencing. RESULTS: The caused gene of ADRP was mapped to 19q13.4 between markers D19S572 and D19S877, with a maximum LOD score of 3.01 at marker D19S418 (recombination fraction = 0). CONCLUSION: The affected gene linked to the 19q13.4 in a Chinese family with ADRP, which is different from other mutations at the same loci in other Chinese families.

Clinical and genetic study of a novel mutation in the REEP1 gene.

OBJECTIVE: To examine the gene mutation associated with clinical phenotype from a Chinese kindred with autosomal dominant hereditary spastic paraplegia (ADHSP). METHOD: To perform linkage analysis and mutation detection. For two affected individual of the family, clinical analysis, electrophysiological examination, and MRI of brain and spinal cord were also performed. RESULT: A novel splice-site mutation (REEP1 c417+1g>a) was identified. Central motor conduction time to the first metatarsal interosseus and anterior tibial muscles were clearly prolonged. Thoracic cord atrophy was found from T1 to T10. CONCLUSION: Our study supports that mutations in REEP1 cause ADHSP and demonstrates genetic heterogeneity in ADHSP. Synapse

[An analysis of mutations causing Gaucher disease in Chinese population].

OBJECTIVE: To review and investigate the relationship of genotype and phenotype in Chinese patients with Gaucher disease (GD). METHODS: The samples were first screened for known mutations as reported previously in Chinese population. Long chain PCR and nested PCR were employed to amplify the segments of glucocerebrosidase functional gene in patients with unknown mutant alleles. The products of nested-PCR were subjected to DNA sequencing to detect the new mutations. RESULTS: Forty kinds of mutations were detected in this panel of patients. The L444P mutation was the most common one accounting for 33.0% of mutant alleles. It was followed by F213I, N188S, V375L and M416V. CONCLUSION: There are at least 40 mutations in Chinese GD patients. The spectrum of mutation is significantly different from that in Caucasians. 70% of mutant alleles have been characterized. It becomes feasible to make clinical and prenatal diagnoses through gene analysis.

[A Chinese girl with fibrodysplasia ossificans progressiva caused by a de novo mutation R206H in ACVR1 gene].

OBJECTIVE: Fibrodysplasia ossificans progressiva (FOP) is a rare autosomal dominant inherited disease caused by mutations of ACVR1 gene and can be inherited from either mother or father. FOP is characterized by the presence of malformations of the big toes and of progressive extra-skeletal ossification. Direct sequence analyses of genomic DNA have demonstrated that there is an identical single nucleotide substitution (c617G-->A, R206H) in the glycine-serine (GS) activation domain of ACVR1 gene, responsible for all affected individuals reported so far. We report a Chinese girl with typical FOP characteristics, in whom the same mutation in ACVR1 was identified. METHODS: Clinical diagnosis was based on physical examination, radiological findings, and biochemical tests. For mutation detection, peripheral blood was obtained with informed consent from the patient and the parents. Genomic DNA was extracted from peripheral blood using standard method. Exon 4 of ACVR1 was amplified by polymerase chain reaction (PCR), and the PCR products were subjected to automatic DNA sequencing. RESULTS: The affected girl is 3-year-old and showed typical clinical manifestations of FOP. She had malformations of the halluces at birth and subsequently progressive extra-skeletal ossification developed at the age of 8 - 9 months. Then, she gradually developed stiffness of the knee joint and neck but remained ambulant. Radiographic changes were observable, e.g., the extra-skeletal ossification was found at cervical spine. Her mother has congenital malformations of the halluces, but had no postnatal progressive extra-skeletal ossification. Her father and other family members are normal. With direct sequencing of the PCR products, a G to A substitution at c617 of ACVR1 (R206H) was detected in the patient only but not in her parents. Paternity analysis suggested that it is a de novo mutation. CONCLUSION: This is the first case reported in a Chinese patient with FOP in the mainland of China, which was confirmed by direct sequencing. Although sporadic cases of FOP have been reported in diverse geographic and ethnic group, the mutations of ACVR1 c617 (R206H) are identical up to now. The presence of mutation hot spot facilitates molecular diagnosis in clinical practice. Genetic detection is important for FOP patients to avoid misdiagnosis and further damages, including those from medical intervention.

[Quantitative analysis of SMN1 and SMN2 genes based on DHPLC: a reliable method for detection of non-homozygous patients with spinal muscular atrophy].

OBJECTIVE: To develop a rapid and reliable approach for testing the copy number of survival motor neuron (SMN) gene and analyze the compound heterozygous deletions of SMN1 gene. METHODS: Peripheral blood samples were collected from 38 non-homozygous deletion pediatric patients with SMA, 30 homozygous deletion patients with SMA, and 35 un-related healthy persons. SMN1 and SMN2 genes were amplified separately with allele-specific PCR (AS-PCR). Meanwhile, two irrelevant genes were amplified as internal quality control respectively. The copy numbers of SMN1 and SMN2 were determined by denaturing high-performance liquid chromatography (DHPLC). RESULTS: (1) A protocol combining multiplex allele-specific PCR and DHPLC was developed to separate SMN1 and SMN2 and to determine the copy numbers of them. The copy numbers of SMN1 and SMN2 varied from 1 to 4 and a clear-cut differentiation among the different copy number ranges could be observed for the two genes. (2) One single copy of SMN1 were detected in 20 of the 38 non-homozygous deletion patients with SMA (52.6%). Heterozygous deletions were determined in these 20 patients. Two copies of SMN2 were detected in 15 of the 20 patients with one copy of SMN1 (75.0%, 15/20). Other 5 of the 20 patients were with 3 copies of SMN2 (25.0%, 5/20). (3) One single copy of SMN1 was detected in 24 of the 30 (80%) parents of SMA patients with homozygous deletion. CONCLUSION: SMN copy number can be rapidly and reliably determined by the method of multiplex AS-PCR combined with DHPLC.