Targeted massively parallel sequencing for congenital generalized lipodystrophy

ABSTRACT Objective: Our aim is to establish genetic diagnosis of congenital generalized lipodystrophy (CGL) using targeted massively parallel sequencing (MPS), also known as next-generation sequencing (NGS). Subjects and methods: Nine unrelated individuals with a clinical diagnosis of CGL were recruited. We used a customized panel to capture genes related to genetic lipodystrophies. DNA libraries were generated, sequenced using the Illumina MiSeq, and bioinformatics analysis was performed. Results: An accurate genetic diagnosis was stated for all nine patients. Four had pathogenic variants in AGPAT2 and three in BSCL2. Three large homozygous deletions in AGPAT2 were identified by copy-number variant analysis. Conclusions: Although we have found allelic variants in only 2 genes related to CGL, the panel was able to identify different variants including deletions that would have been missed by Sanger sequencing. We believe that MPS is a valuable tool for the genetic diagnosis of multi-genes related diseases, including CGL.

Genetic analysis of a pedigree affected with distal hereditary motor neuronopathy V / 中华医学遗传学杂志

OBJECTIVE@#To carry out genetic testing for a family affected with distal hereditary motor neuronopathy V (dHMN V).@*METHODS@#Potential mutations of the GARS and BSCL2 genes were analyzed with PCR and Sanger sequencing. Suspected mutation was verified among unaffected members of the family and 100 healthy controls. Prenatal diagnosis was provided based on the above results.@*RESULTS@#Sequencing analysis has identified a heterozygous c.269C>T (p.S90L) mutation in the BSCL2 gene, which resulted in replacement of Serine (TCG) to Leucine (TTG). The same mutation was found in all other 3 patients from the pedigree but not among unaffected members or the 100 healthy controls. By prenatal diagnosis, the fetus did not carry the above mutation.@*CONCLUSION@#Pathogenic mutation of BSCL2 gene probably underlies the dHMN V in this pedigree, which enabled prenatal diagnosis for the proband.

Unusual facies and recurrent high triglycerides for more than one year in a girl / 中国当代儿科杂志

A girl, aged 1 year and 9 months, was found to have hypertriglyceridemia in the neonatal period, with unusual facies and signs of dark skin all over the body, disappearance of subcutaneous adipose, acanthosis nigricans of the neck, excessive and thick hair, empty cheeks, muscle hypertrophy of the extremities, hepatomegaly, and neutrophil deficiency. Whole exome sequencing of monogenic disorder revealed a homozygote mutation in the BSCL2 gene, c.974 (exon 7)_c.975 (exon 7) insG. Her parents were heterozygotes for this locus. The girl was diagnosed with congenital generalized lipodystrophy (CGL), but the association between CGL and neutrophil deficiency remained unclear. Triglyceride was maintained at a normal level after the treatment with a low-fat and high-carbohydrate diet, and there were no obvious changes in signs. CGL is a rare autosomal recessive systemic disease manifested as disappearance of systemic subcutaneous adipose, muscle hypertrophy of the extremities, and metabolic disorders in the neonatal period, such as high triglycerides, hyperinsulinemia, and hyperglycemia. About 95% of CGL cases are caused by mutations in the AGPAT2 or BSCL2 gene.

Synergistic induction of cancer cell migration regulated by Gbetagamma and phosphatidylinositol 3-kinase

Phosphatidylinositol 3-kinase (PI3K) is essential for both G protein-coupled receptor (GPCR)- and receptor tyrosine kinase (RTK)-mediated cancer cell migration. Here, we have shown that maximum migration is achieved by full activation of phosphatidylinositol 3,4,5-trisphosphate-dependent Rac exchanger 1 (P-Rex1) in the presence of Gbetagamma and PI3K signaling pathways. Lysophosphatidic acid (LPA)-induced migration was higher than that of epidermal growth factor (EGF)-induced migration; however, LPA-induced activation of Akt was lower than that stimulated by EGF. LPA-induced migration was partially blocked by either Gbetagamma or RTK inhibitor and completely blocked by both inhibitors. LPA-induced migration was synergistically increased in the presence of EGF and vice versa. In correlation with these results, sphingosine-1-phosphate (S1P)-induced migration was also synergistically induced in the presence of insulin-like growth factor-1 (IGF-1). Finally, silencing of P-Rex1 abolished the synergism in migration as well as in Rac activation. Moreover, synergistic activation of MMP-2 and cancer cell invasion was attenuated by silencing of P-Rex1. Given these results, we suggest that P-Rex1 requires both Gbetagamma and PI3K signaling pathways for synergistic activation of Rac, thereby inducing maximum cancer cell migration and invasion.

Berardinelli-Seip congenital lipodystrophy.

Berardinelli-Seip congenital lipodystrophy (BSCL) is a very rare genetic disorder characterized by lipoatrophy, hypertriglyceridemia, hepatomegaly and acromegaloid features. On the basis of mutational and haplotype analysis, BSCL families have been classified into three types BSCL 1, BSCL2 and BSCLX. We report Berardinelli-Seip congenital lipodystrophy (BSCL2 type) in three subjects from two unrelated Indian families (family1 and family2). The mutation (c.IVS2 11 A GT G ) found in affected members of family1 is a newly identified mutation. We also report the association of renal anomaly with this new mutation.