Hemophagocytic Lymphohistiocytosis Gene Variants in Severe Aplastic Anemia and Their Impact on Hematopoietic Cell Transplantation Outcomes.

BACKGROUND: Germline genetic testing for patients with severe aplastic anemia (SAA) is recommended to guide treatment, including the use of immunosuppressive therapy and/or adjustment of hematopoietic cell transplantation (HCT) modalities. Hemophagocytic lymphohistiocytosis (HLH) is a life threatening hyperinflammatory condition often associated with cytopenias with autosomal recessive (AR) or X-linked recessive (XLR) inheritance. HLH is part of the SAA differential diagnosis and genetic testing may identify variants in HLH genes in patients with SAA. The impact of pathogenic/likely pathogenic (P/LP) variants in HLH genes on HCT outcomes in SAA is unclear. OBJECTIVES: We aimed to determine the frequency of HLH gene variants in a large cohort of patients with acquired SAA and to evaluate their association(s) with HCT outcomes. STUDY DESIGN: The Transplant Outcomes in Aplastic Anemia project, a collaboration between the National Cancer Institute and the Center for International Blood and Marrow Transplant Research, consists of genomic and clinical data from 824 patients who underwent HCT for SAA between 1989 and 2015. We excluded 140 patients with inherited bone marrow failure syndromes and used exome sequencing data from the remaining 684 patients with acquired SAA to identify P/LP variants in 14 HLH-associated genes (11 AR, 3 XLR) curated using ACMG/AMP criteria. Deleterious variants of uncertain significance (del-VUS) were defined as those not meeting ACMG/AMP P/LP criteria but with damaging predictions in ≥3/5 meta-predictors (BayesDel, REVEL, CADD, MetaSVM and/or EIGEN). Kaplan-Meier estimator was used to calculate the probability of overall survival (OS) after HCT, and cumulative incidence calculator was used for other HCT outcomes accounting for relevant competing risks. RESULTS: There were 46 HLH variants in 49 patients (7.2%; N total=684). Seventeen variants in 19 patients (2.8%) were P/LP; 8 of these were loss of function variants. Among 19 patients with P/LP HLH variants, 16 (84%) had monoallelic variants in genes with AR inheritance, and three had variants in XLR genes. PRF1 was the most frequently affected gene (8/19 patients). We found no statistically significant differences in transplant-related factors between patients with and without P/LP HLH variants. The 5-year survival probabilities were 89% (95% CI=72-99), and 70% (95% CI=53-85%) in patients with P/LP and del-VUS HLH variants, respectively, as compared with 66% (95% CI=62-70) in those without variants (p-log-rank=0.16). The median time to neutrophil engraftment was 16 days for patients with P/LP HLH variants versus 18 days in those with del-VUS or without variants, combined (p-Gray's test=0.01). No statistically significant associations between P/LP HLH variants and the risk of acute or chronic graft-versus-host disease were noted. CONCLUSIONS: In this large cohort of acquired SAA, we found that 2.8% of patients harbor a P/LP variant in an HLH gene. No negative effect on post-HCT survival was noted with HLH gene variants. The small number of patients with P/LP HLH variants limit the study ability to provide conclusive evidence. Yet, our data suggest no need for special transplant considerations for patients with SAA carrying P/LP variants.

Whole exome sequencing identifies novel pathogenic variants in TGM1 and ALOX12B in patients with hereditary ichthyosis.

BACKGROUND: Hereditary ichthyosis is a clinically and genetically heterogeneous disorder associated with more than 50 genes with TGM1, ALOX12B, and ALOXE3 being the most prevalent. Establishing an accurate diagnosis is important for effective genetic counseling and optimal patient management. OBJECTIVE: We studied the diagnostic value of whole exome sequencing (WES) in a small case series with hereditary ichthyosis. METHODS: During a 1-year period, index cases of 5 unrelated families clinically diagnosed with hereditary ichthyosis went through WES, followed by extensive segregation analysis. Prenatal diagnosis (PND) was conducted where indicated. RESULTS: We identified 4 homozygous variants-2 in TGM1 (c.655A > G and c.797A > G) and 2 in ALOX12B (c.527 + 2 T > G and c.1654G > T)-alongside a heterozygous variant in TGM1 (c.428G > A) in 5 families. The variants were all pathogenic/likely pathogenic according to the ACMG classification and segregation analysis, except for c.797A > G in TGM1 which remained a variant of unknown clinical significance. Four variants were novel. All families were referred either during pregnancy or before reproductive planning; 4 benefited from WES as it identified the mutation in the probands and enabled carrier detection in at-risk relatives; PND was conducted in 2 families. CONCLUSION: Our findings further support WES is a powerful tool for the comprehensive, accurate, and rapid molecular diagnosis of hereditary ichthyosis and can offer opportunities for reproductive planning, carrier screening and prenatal diagnosis to at-risk families.

JAK2 V617F mutation and associated chromosomal alterations in primary and secondary myelofibrosis and post-HCT outcomes.

JAK2 V617F is the most common driver mutation in primary or secondary myelofibrosis for which allogeneic hematopoietic cell transplantation (HCT) is the only curative treatment. Knowledge of the prognostic utility of JAK2 alterations in the HCT setting is limited. We identified all patients with MF who received HCT between 2000 and 2016 and had a pre-HCT blood sample (N = 973) available at the Center of International Blood and Marrow Transplant Research biorepository. PacBio sequencing and single nucleotide polymorphism-array genotyping were used to identify JAK2V617F mutation and associated mosaic chromosomal alterations (mCAs), respectively. Cox proportional hazard models were used for HCT outcome analyses. Genomic testing was complete for 924 patients with MF (634 primary MF [PMF], 135 postpolycythemia vera [PPV-MF], and 155 postessential thrombocytopenia [PET-MF]). JAK2V617F affected 562 patients (57.6% of PMF, 97% of PPV-MF, and 42.6% of PET-MF). Almost all patients with mCAs involving the JAK2 region (97.9%) were JAK2V617-positive. In PMF, JAK2V617F mutation status, allele burden, or identified mCAs were not associated with disease progression/relapse, nonrelapse mortality (NRM), or overall survival. Almost all PPV-MF were JAK2V617F-positive (97%), with no association between HCT outcomes and mutation allele burden or mCAs. In PET-MF, JAK2V617F high mutation allele burden (≥60%) was associated with excess risk of NRM, restricted to transplants received in the era of JAK inhibitors (2013-2016; hazard ratio = 7.65; 95% confidence interval = 2.10-27.82; P = .002). However, allele burden was not associated with post-HCT disease progression/relapse or survival. Our findings support the concept that HCT can mitigate the known negative effect of JAK2V617F in patients with MF, particularly for PMF and PPV-MF.

Histological Evaluation of Products of Conception, Who Benefits from It?

Background: Histopathological evaluation of the first trimester pregnancy loss has always been controversial. Although it is recommended, it is not a part of guidelines.Methods: Six hundred eighty-six samples in a referral infertility clinic were evaluated microscopically and categorized. Two hundred ninety-five cases were evaluated by genetic methods (Multiplex Ligation-dependent Probe Amplification).Results: From 569 samples with chorionic villi, 361 cases had history of three or more abortions. 18.3% of this group showed chronic intervillous of unknown etiology (CIUE) and 8.3% revealed intervilli fibrin deposition, both pathologies with a high risk of recurrence. History of a live child was significantly higher in CIUE group. 29% of genetically evaluated cases had a chromosomal abnormality.Conclusion: Histological evaluation of recurrent pregnancy loss could illuminate the cause of abortion in relatively acceptable percentage of cases, especially in mothers with higher number of previous abortion, mothers with a history of live child and in referral centers.

Genetic testing in severe aplastic anemia is required for optimal hematopoietic cell transplant outcomes.

Patients with severe aplastic anemia (SAA) can have an unrecognized inherited bone marrow failure syndrome (IBMFS) because of phenotypic heterogeneity. We curated germline genetic variants in 104 IBMFS-associated genes from exome sequencing performed on 732 patients who underwent hematopoietic cell transplant (HCT) between 1989 and 2015 for acquired SAA. Patients with pathogenic or likely pathogenic (P/LP) variants fitting known disease zygosity patterns were deemed unrecognized IBMFS. Carriers were defined as patients with a single P/LP variant in an autosomal recessive gene or females with an X-linked recessive P/LP variant. Cox proportional hazard models were used for survival analysis with follow-up until 2017. We identified 113 P/LP single-nucleotide variants or small insertions/deletions and 10 copy number variants across 42 genes in 121 patients. Ninety-one patients had 105 in silico predicted deleterious variants of uncertain significance (dVUS). Forty-eight patients (6.6%) had an unrecognized IBMFS (33% adults), and 73 (10%) were carriers. No survival difference between dVUS and acquired SAA was noted. Compared with acquired SAA (no P/LP variants), patients with unrecognized IBMFS, but not carriers, had worse survival after HCT (IBMFS hazard ratio [HR], 2.13; 95% confidence interval[CI], 1.40-3.24; P = .0004; carriers HR, 0.96; 95% CI, 0.62-1.50; P = .86). Results were similar in analyses restricted to patients receiving reduced-intensity conditioning (n = 448; HR IBMFS = 2.39; P = .01). The excess mortality risk in unrecognized IBMFS attributed to death from organ failure (HR = 4.88; P < .0001). Genetic testing should be part of the diagnostic evaluation for all patients with SAA to tailor therapeutic regimens. Carriers of a pathogenic variant in an IBMFS gene can follow HCT regimens for acquired SAA.

Molecular characterization of a large cohort of mucopolysaccharidosis patients: Iran Mucopolysaccharidosis RE-diagnosis study (IMPRESsion).

Mucopolysaccharidoses (MPSs) are rare, heterogeneous inborn errors of metabolism (IEM) diagnosed through a combination of clinical, biochemical, and genetic investigations. The aim of this study was molecular characterization of the largest cohort of Iranian MPS patients (302 patients from 289 unrelated families), along with tracking their ethnicity and geographical origins. 185/289 patients were studied using an IEM-targeted NGS panel followed by complementary Sanger sequencing, which led to the diagnosis of 154 MPS patients and 5 non-MPS IEMs (diagnostic yield: 85.9%). Furthermore, 106/289 patients who were referred with positive findings went through reanalysis and confirmatory tests which confirmed MPS diagnosis in 104. Among the total of 258 MPS patients, 225 were homozygous, 90 harbored novel variants, and 9 had copy number variations. MPS IV was the most common type (34.8%) followed by MPS I (22.7%) and MPS VI (22.5%). Geographical origin analysis unveiled a pattern of distribution for frequent variants in ARSB (c.430G>A, c.962T>C [p.Leu321Pro], c.281C>A [p.Ser94*]), GALNS (c.319G>A [p.Ala107Thr], c.860C>T [p.Ser287Leu], c.1042A>G [p.Thr348Ala]), and IDUA (c.1A>C [p.Met1Leu], c.1598C>G [p.Pro533Arg], c.1562_1563insC [p.Gly522Argfs*50]). Our extensive patient cohort reveals the genetic and geographic landscape of MPS in Iran, which provides insight into genetic epidemiology of MPS and can facilitate a more cost-effective, time-efficient diagnostic approach based on the region-specific variants.

Identification of a novel de novo variant in OTX2 in a patient with congenital microphthalmia using targeted next-generation sequencing followed by prenatal diagnosis.

BACKGROUND: Next-generation sequencing has been proven to be a reliable method for the detection of genetic causes in heterogeneous ocular disorders. In this report an NGS-based diagnostic approach was taken to uncover the genetic etiology in a patient with coloboma and microphthalmia, a highly heterogeneous disease with intrafamilial phenotypic variability. MATERIALS AND METHODS: Next generation sequencing using a targeted panel of 316 genes, was carried out in the proband. Prioritized variants were then identified and confirmed using Sanger sequencing. Prenatal diagnosis of the detected variant was then performed in the family. RESULTS: A novel de novo frameshift variant c.157_164delTTCACTCG (p.Phe53fs) in OTX2, leading to a truncated protein, was identified. Prenatal diagnosis identified the same variant in the fetus. CONCLUSIONS: This report demonstrates the importance of genetic counseling and underscores the efficiency and effectiveness of targeted NGS as a means of detecting variants in inherited eye disorders.

Persistent hypercalcemia with similar familial Hypocalciuric hypercalcemia features: a case report and literature review.

BACKGROUND: Primary hyperparathyroidism (PHPT) and familial hypocalciuric hypercalcemia (FHH) are the most important differential diagnosis of parathyroid hormone (PTH)-dependent hypercalcemia. The clinical features of FHH and PHPT can overlap in some cases. Therefore, these two diseases must be differentiated to prevent unnecessary parathyroidectomy. Here, we present a case that was not entirely matched with any of the known differential diagnoses of hypercalcemia. CASE PRESENTATION: A 19-year-old girl with no history of any disease presented with persistent hypercalcemia without any specific musculoskeletal complaint. We found persistent hypercalcemia in her routine laboratory data from 3 years ago; while no data was available during the childhood period. Her dietary calcium intake was normal. She did not mention any history of renal stone, bone fracture as well as family history of hypercalcemia. Biochemical features showed normal values of serum creatinine, high normal serum calcium (range, 10.3-11.3 mg/dL; (normal range: 8.8-10.4)), and non-suppressed PTH levels (range, 37.2-58.1 pg/mL; (normal range: 10-65)). Serum 25 OH vitamin D level at the first visit was 16.1 ng/mL that treated by vitamin D supplementation. Since then, all 25 OH vitamin D levels were in the acceptable range. After correction of vitamin D deficiency during the follow-up period the calcium creatinine clearance ratio(s) (CCCR) were calculated in the range of 0.009 to 0.014 (means below 1%). The clinical and laboratory data indicate more FHH rather than PHPT. Genetic studies were negative for the common genes associated with FHH (CASR, GNA11, and AP2S1 genes) and multiple endocrine neoplasia type1 (MEN1). On the other hand, no evidence of autoimmunity was found in her to support an autoimmune FHH-like syndrome. Hence, the case did not match completely to any diagnosis of FHH and PHPT, so we decided to follow her. CONCLUSION: We presented a patient with FHH phenotype whose common genetic tests were negative. Further research is needed to ascertain other causes leading to similar manifestations.

Detection of Aneuploidies in Products of Conception and Neonatal Deaths in Iranian Patients Using the Multiplex Ligation-Dependent Probe Amplification (MLPA).

BACKGROUND: Around 70% of all pregnancies (Including 15% of clinically-recognized ones) are lost due to various fetal or maternal disorders. Chromosomal aneuploidies are among the most common causes of pregnancy loss. Standard chromosome analysis using G-banding technique (Karyotype) is the technique of choice in studying such abnormalities; however, this technique is time-consuming and sensitive, and limited by vulnerabilities such as cell culture failure. The use of molecular cytogenetic techniques, including array-based techniques and Multiplex Ligation-Dependent Probe Amplification (MLPA), has been proposed to overcome the limitations of this method to study the products of conception. This study has been designed to investigate the feasibility of using MLPA technique as a standalone genetic testing, with histopathologic examinations and genetic counseling to detect aneuploidies in products of conception and neonatal deaths. METHODS: Forty-two verified fetal and neonatal samples were studies and genetic counseling was scheduled for all parents. Histopathologic examinations were carried out on the products of conception, and appropriate fetal tissues were separated for genetic studies. Following DNA extraction and purification, MLPA was carried out to investigate chromosomal aneuploidies. RESULTS: Nine samples (21.42%) were diagnosed to be affected with aneuploidy. Detected aneuploidies were trisomy 22 (n=3), trisomy 21(n=1), trisomy 18 (n=2), trisomy 16 (n=1), trisomy 13 (n=1), and monosomy of chromosome X (n=1). The MLPA analysis results were conclusive for all of the fetal samples (Success rate: 100%). CONCLUSION: These results suggest that MLPA, as a standalone genetic testing, is an accurate, rapid, and reliable method in overcoming the limitations of standard cytogenetic techniques in genetic investigation of products of conception.

Non-progressive Nonimmune Hydrops Fetalis Caused by a Novel Mutation in GUSB Gene.

Objectives: Mucopolysaccharidosis type VII (MPS VII) or Sly syndrome is a rare autosomal recessive disorder caused by deficiency of ß-glucuronidase enzyme, which is involved in degradation of glycosaminoglycans. The lack of ß-glucuronidase in this lysosomal storage disorder is characterized by various manifestations such as nonimmune hydrops fetalis, spinal deformity, organomegaly, dysostosis multiplex, intellectual disability, and eye involvement. It is caused by a mutation in GUSB gene located on chromosome 7 q11. The current study reported an Iranian female with MPS VII and a novel mutation (c.542G>T, p.Arg181Leu) in GUSB gene.

Rhodopsin gene mutation analysis in Iranian patients with autosomal dominant retinitis pigmentosa.

PURPOSE: Retinitis pigmentosa (RP) is the most common hereditary retinal degeneration and an important cause of visual disability worldwide. Rhodopsin gene is one of the most important genes implicated in autosomal dominant RP (ADRP). In this study, we investigated rhodopsin gene mutations in Iranian patients with ADRP. METHODS: Twenty-one patients from 21 unrelated families with a total of 51 affected members were enrolled in this study. After complete history taking, ophthalmic examination and genetic counseling, peripheral blood samples were obtained. Following genomic DNA extraction, all five exons and intron-exon boundaries of RHO gene were sequenced using Sanger method. Interpretation of detected variants was carried out using appropriate databases and bioinformatic tools. Novel variants were screened in 150 unrelated healthy subjects. RESULTS: Results of direct sequencing revealed that five of 21 patients (23.8%) had mutation in the rhodopsin gene. Two of them had previously identified p.P347L mutation, and three had novel variants including p.L95P, p.R177K and p.N310K. None of these novel variants were detected in healthy controls. The p.L95P variant was associated with predominantly inferior retinal involvement. CONCLUSIONS: Our study showed that mutations of the rhodopsin gene are relatively frequent in Iranian patients with ADRP and could be considered in further researches in the future. The novel p.L95P variant may be associated with a specific pattern of retinal degeneration in this population.

Preimplantation High-Resolution HLA Sequencing Using Next Generation Sequencing.

Hematopoietic stem cell transplantation (SCT) is the only therapeutic option in a number of heritable hematologic disorders and hematologic cancers. Many parents and families fail to find an HLA-identical donor for their affected family member. In such cases, conceiving for a "savior baby" remains the only option, especially in countries without access to national registries. By means of next generation sequencing (NGS) techniques, in a single experiment on single-cell products of in vitro fertilization, a healthy HLA-identical embryo can be implanted in the uterus of a concerned mother. The patient can therefore benefit from cord blood SCT along with confirming that the fetuses are not suffering from the heritable disorder. This study is an attempt to study the feasibility of preimplantation HLA sequencing on single blastomeres using NGS. Two couples who had previously undergone preimplantation genetic diagnosis of ß-thalassemia and their overall 10 embryos were studied and their 5 HLA loci were typed in high resolution through multiple displacement amplification and NGS of single cells. For 88.9% of the 90 HLA alleles, conclusive HLA typing in 4 digit sets was made. HLA alleles were typed; 1 ambiguity in the allelic group and 4 ambiguities in the protein level were observed that were then unraveled by haplotype analysis. Amplification efficiency was 93.3% with an allele drop-out (ADO) rate of 22.2% (6 alleles dropped from a maximum of 27 possible ADOs). In this study the feasibility of a new method of preimplantation HLA sequencing via combining the state-of-the-art techniques used in single-cell whole genome amplification, preimplantation genetic diagnosis, and high-resolution HLA typing by NGS has been shown. This method can make preimplantation HLA sequencing a practicable technique in families desperate for an HLA-matched donor.

A novel ACVR1 mutation detected by whole exome sequencing in a family with an unusual skeletal dysplasia.

"Disorganized Development of Skeletal Component" (DDSC) is a group of genetic skeletal dysplasia, caused by mutations in 9 genes including ACVR1. The most known ACVR1-related disorder is fibrodysplasia ossificans progressiva (FOP). FOP variants are frequently encountered with diagnostic challenges due to overlapping clinical manifestations and variable severity. Application of high throughput sequencing methods can overcome these limitations by simultaneous investigation of the entire ACVR1 gene together with other genes involved in disorders with similar manifestations. A 33-year-old man with an unusual skeletal dysplasia and no previous clinical diagnosis is presented in this study. Whole exome sequencing detected a novel c.737T>A (p.Phe246Tyr) mutation in ACVR1 gene. Detailed targeted variant analysis in 226 known genes associated with genetic skeletal disorders together with more specific targeted analysis in 9 genes associated with DDSC ruled out the involvement of other investigated genes. Proband's phenotypically normal father and brother had the same mutation in whom subsequent investigations showed subclinical radiographic findings. The clinical manifestations, the disease course, and the molecular findings of involvement of ACVR1 gene in this family are suggestive of "FOP variant" or an unusual ACVR1-related skeletal dysplasia. Moreover, this report has demonstrated the critical role of the next generation sequencing technique in characterizing such a rare disorder with variable and even no clinical manifestations, providing the opportunity for effective preventive measures such as preimplantation genetic diagnosis.

Prenatal Diagnosis of Tyrosinemia Type 1 Using Next Generation Sequencing.

Prenatal diagnosis using conventional molecular genetic techniques may be encountered with some limitations when the disease causing mutation is unknown. Here, we report on prenatal diagnosis of tyrosinemia in a family with consanguineous marriage and two affected children in whom no disease causing mutation had been identified before pregnancy. Mutation analyses of three genes associated with tyrosinemia including FAH, TAT and HPD were carried out in the fetal DNA sample using Next Generation Sequencing. A heterozygous nonsense mutation (p.Arg237Ter) in FAH gene was detected in the fetus. Further investigations suggested that the fetus was carrier of tyrosinemia type 1. This study demonstrates the successful application of Next Generation Sequencing in prenatal diagnosis, when the time is a limiting factor, more than one (especially large) responsible genes are involved, a "founder" or a "previously detected" mutation is not present and hence the conventional molecular genetic investigations cannot be employed.

Increasing the yield in targeted next-generation sequencing by implicating CNV analysis, non-coding exons and the overall variant load: the example of retinal dystrophies.

Retinitis pigmentosa (RP) and Leber congenital amaurosis (LCA) are major causes of blindness. They result from mutations in many genes which has long hampered comprehensive genetic analysis. Recently, targeted next-generation sequencing (NGS) has proven useful to overcome this limitation. To uncover "hidden mutations" such as copy number variations (CNVs) and mutations in non-coding regions, we extended the use of NGS data by quantitative readout for the exons of 55 RP and LCA genes in 126 patients, and by including non-coding 5' exons. We detected several causative CNVs which were key to the diagnosis in hitherto unsolved constellations, e.g. hemizygous point mutations in consanguineous families, and CNVs complemented apparently monoallelic recessive alleles. Mutations of non-coding exon 1 of EYS revealed its contribution to disease. In view of the high carrier frequency for retinal disease gene mutations in the general population, we considered the overall variant load in each patient to assess if a mutation was causative or reflected accidental carriership in patients with mutations in several genes or with single recessive alleles. For example, truncating mutations in RP1, a gene implicated in both recessive and dominant RP, were causative in biallelic constellations, unrelated to disease when heterozygous on a biallelic mutation background of another gene, or even non-pathogenic if close to the C-terminus. Patients with mutations in several loci were common, but without evidence for di- or oligogenic inheritance. Although the number of targeted genes was low compared to previous studies, the mutation detection rate was highest (70%) which likely results from completeness and depth of coverage, and quantitative data analysis. CNV analysis should routinely be applied in targeted NGS, and mutations in non-coding exons give reason to systematically include 5'-UTRs in disease gene or exome panels. Consideration of all variants is indispensable because even truncating mutations may be misleading.

Biochemical responses of juvenile European sturgeon, (Huso huso) to a sub-lethal level of copper and cadmium in freshwater and brackish water environments.

In Caspian Sea basin, sturgeons spend the larval and juvenile stages in freshwaters of rivers and then, they migrate to brackish waters of the sea where they grow and mature. With regard to the elevation of the metal concentrations in coastal waters and sediments of the Caspian Sea and its adjacent rivers, it is likely that juvenile sturgeon are exposed to sub-lethal levels of metals during seawater entry process. We compared the biochemical responses of juvenile European sturgeon, (Beluga, Huso huso) exposed to a sub-lethal level of copper (Cu, 20 µg/L) and cadmium (Cd, 300 µg/L) in freshwater (FW, 0 ppt) and brackish water (BW, 11 ppt) for seven days. The results showed that the levels of plasma glucose increased significantly in BW and in all metal exposed groups. Also, plasma cortisol concentrations showed significant increases when juveniles were exposed to BW, Cu(FW/BW) and Cd(BW). The activity of liver superoxide dismutase (SOD) decreased significantly in BW compared with FW. Moreover, Cu and Cd exposure enhanced the activity of SOD in BW, while SOD did not show any changes in FW. The levels of tissue and plasma proteins as well as plasma triiodothyronine (T3), thyroxine (T4) and liver Catalase (CAT) activity remained constant when animals were exposed to Cu/Cd in both FW and BW environments. Our data indicate that exposure of juvenile beluga to BW stimulated the general biochemical responses of stress such as cortisol and glucose, while sub-lethal exposure to Cu and Cd caused oxidative stress in BW environment but not in FW.

Heterozygosity assessment of five STR loci located at 5q13 region for preimplantation genetic diagnosis of spinal muscular atrophy.

Preimplantation genetic diagnosis (PGD) has been considered as an alternative to prenatal diagnosis for prevention of genetic disorders while avoiding the subsequent termination of pregnancy. However, the limited amount of template DNA available in a single diploid cell used for PGD leads to number of problems including an increased incidence of detectable contamination; amplification failure and allele drop out. Due to their highly polymorphic and amplifiable characteristics, short tandem repeat (STR) analysis has been proposed as a mean to overcome these limitations. Heterozygosity of the applied STRs is of paramount importance in their informativity, and should therefore be studied in any certain population. Here, for the first time, we report on the heterozygosity analysis of five STR markers (D5S1408, D5S1417, D5S610, D5S629 and D5S637) flanking to SMA gene region, to examine their applicability in the PGD for SMA disease. We have also investigated other statistical features of these markers and found that all of the five studied STRs were informative and four meet the Hardy-Weinberg equilibrium for the studied population. Furthermore, our results propose that similar approaches can be used for the PGD of other single gene disorders.

Familial Williams-Beuren syndrome ascertained by screening rather than targeted diagnosis.

Williams-Beuren syndrome (WBS), a contiguous gene deletion syndrome, mostly occurs sporadically. Although a few cases of familial WBS have been reported in the literature, molecular confirmation of the deletion has not been carried out in all of them. Here, we report on the eighth clinically and molecularly confirmed inherited WBS detected in a family with 'familial mental retardation.' A comprehensive screening approach to mental retardation that included stepwise karyotyping, assessment for fragile-X syndrome, subtelomeric rearrangements and known microdeletion/microduplication syndromes, and a genome-wide array-CGH study was applied. The father, the mother, and their daughter were all mentally handicapped with nonspecific clinical manifestations and dysmorphic features. The first child of the family died from multiple congenital anomalies. The father and his daughter, who had never been suspected to have WBS, were diagnosed as having a deletion of the WBS critical region. No other abnormalities were detected in the family. Unlike other previously reported cases, in which the disease was ascertained on the basis of clinical manifestations, the present report represents an example of the detection of cryptic chromosomal abnormalities in mental retardation patients by the stepwise application of high-throughput screening methods.

"Familial" versus "sporadic" intellectual disability: contribution of subtelomeric rearrangements.

BACKGROUND: Cryptic subtelomeric rearrangements have been proposed as a significant cause of sporadic intellectual disability (ID) but the role of such aberrations in familial ID has not yet been studied. As positive family history of ID had been proposed as an important and significant predicting factor of subtelomeric rearrangements, it was assumed that the contribution of subtelomeric aberrations in familial ID would be much more than the sporadic ones. Three hundred and twenty two patients from 102 unrelated families with more than two ID patients in the first degree relatives have been investigated. Assessment of subtelomeric rearrangements were carried out using Multiplex Ligation-Dependent Probe Amplification (MLPA) technique. Detected aberrations were then confirmed by Fluorescence in Situ Hybridization (FISH) method. RESULTS: Among the families studied, 27.4% had 4-12, 36.3% had 3 and 36.3% had 2 affected individuals in the first degree relatives. One unbalanced translocation and 4 polymorphic changes were detected. The prevalence of clinically significant subtelomeric rearrangements was 0.98%. CONCLUSION: This is the first investigation of subtelomeric aberrations in a large sample set of familial ID patients. Our results show that the contribution of subtelomeric rearrangements to familial ID is not as much as what had been determined for sporadic ones in the literature. Moreover, this study shows that the positive family history by alone, cannot be the most important and determining indicator of subtelomeric aberrations while it would be a good predicting factor when associated with dysmorphism or congenital malformations. These findings propose that other cryptic chromosomal abnormalities or even single gene disorders may be the main cause of familial ID rather than subtelomeric aberrations.

"Familial" versus "Sporadic" intellectual disability: contribution of common microdeletion and microduplication syndromes.

BACKGROUND: Interstitial Microdeletion and Microduplication syndromes have been proposed as a significant cause of sporadic intellectual disability (ID) but the role of such aberrations in familial ID has not yet been investigated. As the balanced chromosomal abnormalities commonly lead to the recurrent ID or multiple congenital anomalies, this study was designed to evaluate whether it was justified to investigate such aberrations in familial ID patients. Three hundred and twenty eight patients from 101 unrelated Iranian families with more than two ID patients in the first-degree relatives, have been investigated. Assessment of a panel of 21 common Microdeletion and Microduplication syndromes (CMMS) was carried out using Multiplex Ligation-Dependent Probe Amplification (MLPA) technique. RESULTS: Among the families studied, 27.7% had 4-12, 35.6% had 3 and 36.6% had 2 affected individuals in the first-degree relatives. An autosomal dominant inheritance of Williams-Beuren syndrome (WBS) was detected in a family with no clinical suspicion of WBS. The prevalence of CMMS was therefore,0.99%. CONCLUSION: This is the first investigation of a panel of CMMS in a large sample set of "familial ID patients". The findings of this study showed the low prevalence of CMMSs in "familial ID" patients in spite of the significant contribution of such aberrations in "sporadic ID" which has a very useful practical impact by avoiding unnecessary diagnostic tests in "familial ID" patients.