Preimplantation genetic testing guidelines of International Society of Reproductive Genetics

The International Society of Reproductive Genetics(ISRG)assembled a workgroup made up of clinicians,clinical laboratory directors,and scientists for the purpose of creating the guidelines for preimplantation genetic testing(PGT).The most up-to-date information and clinical insights for the optimal PGT practice were incorporated in these guidelines.Recommendations are provided for embryologists,medical geneticists,clinical laboratorians,and other healthcare providers to improve the wellbeing of patients seeking assisted reproductive treatment and their offspring.

Implementing comprehensive genetic carrier screening in China―Harnessing the power of genomic medicine for the effective prevention/management of birth defects and rare genetic diseases in China

Carrier screening had been demonstrated as a powerful practice in preventing selected severe genetic disorders. This practice is expanding its scope and impact in the era of next-generation sequencing. Empirical and theoretical data support the utility of expanded carrier screening. The authors propose a comprehensive carrier screening program as a main component of the first-tier measure in preventing severe genetic disorders and birth defects in China. We discussed the key principles and important aspects to ensure the success of such a program. The authors believe this program will play a pivotal role in our endeavor for a healthier nation.

A report on a girl of Noonan syndrome 9 presenting with bilateral lower limbs lymphedema

To the Editor:Noonan syndrome (NS)is a common genetic multisystem disorder caused by aberrant signal flux through mitogen-activated protein kinase (Ras-MAPK) and has an estimated prevalence of 1 in 1000-2500[1]. It was characterized by Jacqueline Noonan,who reported nine patients with pulmonary valve stenosis,small stature, hypertelorism,mild intellectual disability,webbed neck, undescended testes,and skeletal malformations[2], The lymphatic disorders are rare,it can happen at any age but most instances happen at birth,which are known to be particularly associated with NS,though it has not been well characterized to date.Gene mutations identified in individuals with the NS,regulate impertinently the Ras/ MAPK signal transduction pathway and they can currently explain 70 %of the NS cases.Therefore,it is very important for genetic counseling and life management.[2] Here,we reported a rare Noonan syndrome 9 patient in Asian with significant,persistent and progressive bilateral lower limb dysplasia.

Complete genome sequence of methicillin-sensitive Staphylococcus aureus containing a heterogeneic staphylococcal cassette chromosome element

Staphylococcus aureus is a common human bacterium that sometimes becomes pathogenic,causing serious infections.A key feature of S.aureus is its ability to acquire resistance to antibiotics.The presence of the staphylococcal cassette chromosome(SCC) element in serotypes of S.aureus has been confirmed using multiplex PCR assays.The SCC element is the only vector known to carry the mecA gene,which encodes methicillin resistance in S.aureus infections.Here,we report the genome sequence of a novel methicillin-sensitive S.aureus(MSSA) strain:SCC-like MSSA463.This strain was originally erroneously serotyped as methicillin-resistant S.aureus in a clinical laboratory using multiplex PCR methods.We sequenced the genome of SCC-like MSSA463 using pyrosequencing techniques and compared it with known genome sequences of other S.aureus isolates.An open reading frame(CZ049;AB037671) was identified downstream of attL and attR inverted repeat sequences.Our results suggest that a lateral gene transfer occurred between S.aureus and other organisms,partially changing S.aureus infectivity.We propose that attL and attR inverted repeats in S.aureus serve as frequent insertion sites for exogenous genes.

Next-generation sequencing based molecular testing is an equalizer for diagnostic service of rare genetic disorders in China

The traditional approach of clinical genetic practice,known as the phenotype-first approach,usually starts with a thorough review of electronic medical records of the patient and a complete evaluation of patient's clinical presentation,as well as a survey of family history.Often more than one experienced clinical geneticists will order a variety of additional laboratory or imaging tests to obtain relevant information in order to reach a reasonable clinical diagnosis.Finally,molecular testing often helps to confirm the clinical diagnosis.This practice requires the availability of electronic medical records,well trained clinical geneticists who are able to perform relevant clinical evaluation,order appropriate tests and understand the molecular reports.These critical components of clinical genetics are mostly lacking in China today,1 as a consequence,most of patients with genetic condition do not receive a proper evaluation by clinical geneticists,only a small percent of patients received a clinical diagnosis and the majority remains undiagnosed for life.

类SCC样甲氧西林敏感性金黄色葡萄球菌的基因组学分析

金黄色葡萄球菌(Staphylococcus aureus,S.aureus),作为一种常见的致病菌常可导致严重感染性疾病.金黄色葡萄球菌的主要特点是易产生耐药性.临床上运用多重PCR方法对S.aureus耐药菌株进行分型.SCC作为一种mecA基因的转运载体,介导金黄色葡萄球菌产生耐药性.本研究报道了一株新甲氧西林敏感性金黄色葡萄球菌的全基因组序列信息,即类SCC样MSSA463菌株,经多重PCR方法,该菌株被误鉴定为耐甲氧西林金黄色葡萄球菌,结果与药敏结果相冲突.为此,运用焦磷酸测序方法完成了该菌株的全基因组测序,并与已知金黄色葡萄球菌的基因组序列信息不同,发现可读框(CZ049;AB037671)存在于attL,attR反向重复序列的临近下游.这些结果提示,在金黄色葡萄球菌与其他微生物之间可能存在一种水平基因转移,并改变了金黄色葡萄球菌对药物的敏感性,推测attL,attR反向重复序列可能作为外源性基因的插入部位而存在.