Suchergebnisse

The pace of discovery in the field of human genetics has increased exponentially in the last 30 years. We have witnessed the completion of the Human Genome Project, the identification of hundreds of disease-causing genes, and the dawn of genomic medicine (clinical care based on genomic information). Reduction of DNA sequencing costs, thanks to the so-called "next generation sequencing" technologies, is driving a shift towards the era of "personal genomes", but scientific as well as ethical challenges ahead are countless. We provide an overview on the classification of genetic tests, on informed consent procedures in the context of genetic counseling, and on specific ethical issues raised by the implementation of new DNA sequencing technologies.

Abstract

Background
Heterozygous mutations of MYH9, encoding the Non-Muscular Myosin Heavy Chain-IIA (NMMHC-IIA), cause a complex disorder named MYH9-related disease, characterized by a combination of different phenotypic features. At birth, patients present platelet macrocytosis, thrombocytopenia and leukocyte inclusions containing NMMHC-IIA. Moreover, later in life some of them develop the additional features of sensorineural hearing loss, cataracts and/or glomerulonephritis that sometimes leads to end stage renal failure.


Results
To clarify the mechanism by which the mutant NMMHC-IIA could cause phenotypic anomalies at the cellular level, we examined the effect of transfection of the full-length mutated D1424H MYH9 cDNAs. We have observed, by confocal microscopy, abnormal distribution of the protein and formation of rod-like aggregates reminiscent of the leukocyte inclusions found in patients. Co-transfection of differently labeled wild-type and mutant full-length cDNAs showed the simultaneous presence of both forms of the protein in the intracellular aggregates.


Conclusion
These findings suggest that the NMMHC-IIA mutated in position 1424 is able to interact with the WT form in living cells, despite part of the mutant protein precipitates in non-functional aggregates. Transfection of the entire WT or mutant MYH9 in cell lines represents a powerful experimental model to investigate consequences of MYH9 mutations.

8 páginas, 2 figuras. ; In 2015-2016, we and others reported ALDH18A1 mutations causing dominant (SPG9A) or recessive (SPG9B) spastic paraplegia. In vitro production of the ALDH18A1 product, Δ1 -pyrroline-5-carboxylate synthetase (P5CS), appeared necessary for cracking SPG9 disease-causing mechanisms. We now describe a baculovirus-insect cell system that yields mgs of pure human P5CS and that has proven highly valuable with two novel P5CS mutations reported here in new SPG9B patients. We conclude that both mutations are disease-causing, that SPG9B associates with partial P5CS deficiency and that it is clinically more severe than SPG9A, as reflected in onset age, disability, cognitive status, growth, and dysmorphic traits ; Whole‐exome sequencing analysis was funded by a "Fondazione del Monte" grant to Professor MS for clinical exome sequencing applied to the diagnosis of ultrarare/orphan inherited diseases. The Genetic Bank (Biobanca del Laboratorio di Genetica Umana IRCCS Gaslini), member of the Network Telethon of Genetic Biobanks (Project No. GTB12001), funded by Telethon Italy, provided us with specimens. VR was supported by grants of the Fundación Inocente Inocente and of the Spanish Government (MINECO BFU2017‐84264‐P). ; Peer reviewed

8 páginas, 4 figuras, 1 tabla ; Supported by Grants from the Comitato Telethon Fondazione Onlus, the Amministrazione Autonoma dei Monopoli di Stato, the city of Gubbio, Italy (grant numbers GGP06209 and GGP10121), the Italian Ministry of Health ('Identification of tumor biomarkers through a biologydriven integrated approach'), and the Spanish and the Valencian Governments (grants BFU2011-30407 and Prometeo II/2014/029, respectively). NG holds a contract of CIBERER. ; Peer reviewed