Novel LAMA2 gene mutations associated with merosin-deficient congenital muscular dystrophy

Background: Merosin-deficient congenital muscular dystrophy [MDC1A] is a rare autosomal recessive genetic disease occurred due to mutations in the LAMA2 gene. This study investigated the molecular genetics of three Iranian MDC1A patients who manifested hypotonia, muscle weakness at birth, elevated levels of creatine kinase, and normal magnetic resonance imaging before the age of six months

Methods: Peripheral blood samples were collected from three unrelated patients and their families after obtaining informed written consents. Genomic DNA was extracted and sequenced using next-generation sequencing, followed by Sanger confirmation

Results:Sequencing results revealed a known missense mutation, c.8665G>A, and two novel heterozygous sequencing variants affecting splicing, c.397-4-c.478del and c.7452-1G>A, in the LAMA2 gene. Reverse transcriptase-PCR analysis showed that a new intronic variant, c.7452-1G>A, produced aberrant splicing pattern in the patient

Conclusions: This study expands the mutation spectrum of LAMA2 and assists in the diagnosis, genetic counseling, and prenatal diagnosis of the affected families

Genetic analysis of Iranian patients with familial hypercholesterolemia

Background: Familial hypercholesterolemia [FH] is a frequent autosomal dominant disorder of lipoprotein metabolism. This disorder is generally caused by mutations in low-density lipoprotein receptor [LDLR], apolipoprotein B 100 [APOB], and proprotein convertase subtilisin/kexin type 9 [PCSK9] genes. In the present study, we aimed at identifying the common LDLR and APOB gene mutations in an Iranian population

Methods: Eighty unrelated Iranian patients with FH entered the study, based on Simon Broome diagnostic criteria. All samples were screened for two common APOB gene mutations, including R3500Q and R3500W, by the means of ARMS-PCR and PCR- RFLP assays, respectively. In addition, exons 3, 4, 9, and 10 of LDLR gene were sequenced in all patients

Results: A novel mutation in exon 3 [C95W] and a previously described mutation in exon 4 [D139H] of LDLR gene were found. Three previously reported polymorphisms in LDLR gene as well as three novel polymorphisms were detected in the patients. However, in the studied population, no common mutations were observed in APOB gene

Conclusion: The results of our study imply that the genetic basis of FH in Iranian patients is different from other populations

Functional analysis of a novel splicing mutation in the mutase gene of two unrelated pedigrees

Objective: methylmalonic acidura [MMA] is a rare autosomal recessive inborn error of metabolism. In this study we present a novel nucleotide change in the mutase [MUT] gene of two unrelated Iranian pedigrees and introduce the methods used for its functional analysis

Materials and Methods: two probands with definite diagnosis of MMA and a common novel variant in the MUT were included in a descriptive study. Bioinformatic prediction of the splicing variant was done with different prediction servers. Reverse transcription- polymerase chain reaction [RT-PCR] was done for splicing analysis and the products were analyzed by sequencing

Results: the included index patients showed elevated levels of propionylcarnitine [C3]. Urine organic acid analysis confirmed the diagnosis of MMA, and screening for mutations in the MUT revealed a novel C to G variation at the 3' splice acceptor site in intron 12. In silico analysis suggested the change as a mutation in a conserved sequence. The splicing analysis showed that the C to G nucleotide change at position -3 in the acceptor splice site can lead to retention of the intron 12 sequence

Conclusion: this is the first report of a mutation at the position -3 in the MUT intron 12 [c.2125-3C>G]. The results suggest that the identified variation can be associated with the typical clinical manifestations of MMA

Report of a case with trisomy 9 mosaicism

Trisomy 9 is a rare chromosome disorder with high neonatal mortality. It is often seen in mosaic form. Most patients who survive are severely mentally retarded. The main features of this syndrome are "bulbous" nose, microphthalmia, dislocated limbs, and other anomalies of skeletal, cardiac, genitourinary, and central nervous system. Most patients have developmental and cognitive impairment. Patients with mosaicism survive longer than non-mosaics, but it was believed that the degree of mosaicism in lymphocytes or fibroblasts does not associate with survival or degree of impairment. In this report, we present a 2,5-year-old male case of mosaic trisomy 9, to show the wide range of clinical findings in this chromosome disorder. The patient had cardiac anomalies, inguinal hernia, and undescendent testes. He had low-set slightly malformed ears, deeply-set malformed eyes, small palpebral fissures, micrognathia, developmental delay and unilateral optic hypoplasia. The most prominent facial anomaly in this patient was eye anomalies. Cytogenetic analysis with G banding showed karyotype 47XY,+9 in 44% of peripheral lymphocytes examined [47XY,+9[22], 46XY[28]]. His parents' karyotypes were normal. Moderate developmental delay, which was detected in this patient shows that the range of motor and cognitive impairment in this chromosomal disorder is quite broad. This fact should be considered in genetic counseling as well as prenatal diagnosis of this chromosomal disorder

Homozygosity for a robertsonian translocation [13q;14q] in a phenotypically normal 44, XX female with a history of recurrent abortion and a normal pregnancy outcome

Background: Robertsonian translocations are structural chromosomal abnormalitiescaused by fusion of two acrocentric chromosomes. In carriers of such translocations,different modes of segregations would result in the formation of either balanced [alternatesegregation mode] or unbalanced [adjacent 1, adjacent 2, and 3:1 segregationmodes] gametes. In addition, there is an increased risk for imprinting disorders intheir offspring. Although it has been estimated that 1/1000 healthy persons carry aRobertsonian translocation, homozygosity for this type of structural chromosomalabnormality has been reported rarely. Most of reported cases are phenotypicallynormal but experience adverse pregnancy outcomes

Case Presentation: In this paper, a report was made on a normal female with a historyof 4 consecutive first trimester fetal losses and a normal son referred to Centerfor Comprehensive Genetics Services, Tehran, Iran, in summer 2015. Cytogeneticanalyses of proband and her infant showed 44,XX, der[13;14][q10;q10]x2 and 45,XY, der[13;14][q10;q10], respectively. Parents of proband have been shown to have45,XY,der[13q;14q] and 45,XX,der[13q;14q] karyotypes, respectively

Conclusion: The present report was in agreement with the few reports of homozygosityfor Robertsonian translocation which demonstrated normal phenotypes forsuch persons and possibility of giving birth to phenotypically normal heterozygotecarriers of Robertsonian translocations

[MIR-520d expression analysis in breast cancer]

Breast cancer is the most common cancer in women. Non-coding RNAs especially miRNAs have important regulatory roles in cancer. MiRNAs are 21-24 nucleotides which have different levels of expression between tumors and normal tissues. In this study, we have analyzed expression level of miR-520d in three different groups of breast cancer. Fifty nine samples were divided into different groups according to their immunohistochemistry [IHC] classification: estrogen receptor [ER] positive and/or progesterone receptor [PR] positive group [as group I]; human epidermal growth factor receptor 2 [HER2] positive group [as group II]; and Triple negative group [as group III]. After small RNA extraction from tissues, cDNAs were synthesized and Real time RTPCR carried out using DNA binding dye. Expression levels were analyzed by LinRegPCR and REST software. MiR-520d under- expressed in all of three different groups. The expression ratio in groups I, II, and III were 0.193, 0.167, 0.21, respectively, but only the result from group II was significant [P=0.017]. According to the different clinicopathological status of breast cancer, miR-520d underexpressed significantly not only in patients with metastatic lymph node [P=0.019] but also in patients which have cancer at stage three [P=0.036]. In this study, we found that miR-520d possibly acts as a tumor suppressor. It may be useful for diagnosis of tumor from normal tissue. In addition, miR-520d significantly underexpressed in HER-2 positive group of breast cancers. Therefore, it may be useful as an additional diagnostic test in this group of breast tumors along with other biomarkers.