Image1_Case report: PIK3CA somatic mutation leading to Klippel Trenaunay Syndrome and multiple tumors.JPEG

We report a case of Klippel Trenaunay Syndrome that was monitored both clinically and molecularly over a period of 9 years. A somatic mosaic mutation of PIK3CA (p(E545G)) was identified using both cfDNA NGS liquid biopsy and tissue biopsy. At the age of 56, due to intervening clonal mutations in PIK3CA background, she developed a squamous cell carcinoma in the right affected leg which was treated surgically. Nine years later, lung bilateral adenocarcinoma arose on PIK3CA mutated tissues supported by different clonal mutations. One year later, the patient died from metastases led by a new FGFR3 clone unresponsive to standard-of-care, immunotherapy-based. Our results highlight the presence of a molecular hallmark underlying neoplastic transformation that occurs upon an angiodysplastic process and support the view that PIK3CA mutated tissues must be treated as precancerous lesions. Importantly, they remark the effectiveness of combining cfDNA NGS liquid and tissue biopsies to monitor disease evolution as well as to identify aggressive clones targetable by tailored therapy, which is more efficient than conventional protocols.</p

DataSheet1_Case report: PIK3CA somatic mutation leading to Klippel Trenaunay Syndrome and multiple tumors.docx

We report a case of Klippel Trenaunay Syndrome that was monitored both clinically and molecularly over a period of 9 years. A somatic mosaic mutation of PIK3CA (p(E545G)) was identified using both cfDNA NGS liquid biopsy and tissue biopsy. At the age of 56, due to intervening clonal mutations in PIK3CA background, she developed a squamous cell carcinoma in the right affected leg which was treated surgically. Nine years later, lung bilateral adenocarcinoma arose on PIK3CA mutated tissues supported by different clonal mutations. One year later, the patient died from metastases led by a new FGFR3 clone unresponsive to standard-of-care, immunotherapy-based. Our results highlight the presence of a molecular hallmark underlying neoplastic transformation that occurs upon an angiodysplastic process and support the view that PIK3CA mutated tissues must be treated as precancerous lesions. Importantly, they remark the effectiveness of combining cfDNA NGS liquid and tissue biopsies to monitor disease evolution as well as to identify aggressive clones targetable by tailored therapy, which is more efficient than conventional protocols.</p

<i>Kras</i>-4A levels in lung tumors from 80 urethane-treated ABF4 mice are controlled by <i>Pas1</i> locus.

<p>(a) Expression QTL analysis of <i>Kras</i> transcripts showed that square-root-transformed levels of <i>Kras</i>-4A linked to the <i>Pas1</i> locus (LOD = 4.5). No significant linkage was observed for the <i>Kras</i>-4B mRNA isoform. Tick marks show the position of the genotyped markers in a recombinational map. Horizontal line at LOD = 2.55 marks the 95% threshold for significance. (b) Relative expression levels of the <i>Kras</i>-4A isoform according to rs6265387 genotype. Mice homozygous for the A/J-derived susceptible allele (GG, n = 37) had higher levels than either heterozygous animals (AG, n = 34) or mice homozygous for the C57BL/6 resistant allele (AA, n = 9). ***<i>P</i><0.001, **<i>P</i><0.01 vs. GG mice, ANOVA followed by Tukey's test for multiple comparisons. Values are means and SE.</p

Differential allelic expression of <i>Kras</i>-4A isoform indicates the existence of functional polymorphisms in <i>Kras</i> gene.

<p>Allelic ratios were determined by pyrosequencing for rs30022167 and rs29968550, which map in a region of the <i>Kras</i> 3′-UTR common to both isoforms, on genomic DNA and cDNA from normal lung tissue (n = 20) and lung tumor specimens (n = 15) from ABF4 heterozygous mice. Values are mean and SE; *** P<0.001, two-sided Welch's t test (see <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1004307#pgen-1004307-t001" target="_blank"><b>Table 1</b></a> for complete data).</p

<i>Kras</i>-4A expression is highly controlled by <i>Pas1</i> locus in normal lung.

<p>(a) Genetic linkage analysis of expression levels (square root transformed) of two <i>Kras</i> transcripts in 111 untreated ABF4 mice showed that the <i>Kras</i>-4A isoform was strongly linked to the <i>Pas1</i> locus (LOD score = 23.2) whereas the <i>Kras</i>-4B isoform showed a weaker linkage (LOD score = 4.1). Horizontal line at LOD = 2.13 marks the threshold for significance. Tick marks show the position, in a recombinational map, of the nine genotyped markers spanning from chromosome 6 position 96.7 Mb to 148.3 Mb. (b, c) Expression levels of <i>Kras</i>-4A and -4B in normal lung tissue, by genotype for the 37-bp insertion mutation common to both isoforms. The A/J-derived susceptible allele is negative (-) for the insertion whereas the C57BL/6 allele is positive (ins); 30 mice were -/-, 52 ins/-, and 29 ins/ins. (b) For <i>Kras</i>-4A, <i>P</i> = 9.7×10⁻¹⁴, ANOVA. Tukey's test for multiple comparisons, *<i>P</i> = 0.01, ***<i>P</i> = 7.4×10⁻¹⁴ vs. -/-. (c) For <i>Kras</i>-4B, <i>P</i> = 9.7×10⁻⁵, ANOVA. Tukey's test for multiple comparisons, **<i>P</i> = 1.5×10⁻⁴ vs. -/-. Values are means and SE.</p

<i>Kras</i>-4A is expressed at higher levels in susceptible (A/J) than resistant (C57BL/6) strains.

<p>Expression levels of <i>Kras</i>-4A (a) and <i>Kras</i>-4B (b) isoforms were measured by qPCR in normal lung of 11 A/J and 11 C57BL/6 mice. * <i>P</i> = 7.1×10⁻⁵, ANOVA. The line within each box represents the median of square root transformed values; upper and lower edges of each box are 75^th and 25^th percentiles, respectively; upper and lower bars indicate the highest and lowest values less than one interquartile range from the extremes of the box.</p

Lung tumor multiplicity in 183 urethane-treated male ABF4 mice is controlled by the <i>Pa</i>s<i>1</i> locus.

<p>(a) LOD score plot for chromosome 6 on which a quantitative trait locus (QTL) for lung tumor multiplicity (square root transformed values) mapped to the telomeric region. The QTL peak (LOD score = 48, phenotypic variance explained = 69%) overlapped with the <i>Pas1</i> locus. Tick marks show the position of 37 genotyped markers, including rs6265387 at the QTL peak. Horizontal line indicates the 95% LOD threshold. (b) Number of lung tumors per animal, grouped according to genotype at rs6265387. Mice homozygous for the A/J-derived allele (GG; n = 59) had more tumors than either heterozygous animals (n = 82) or mice homozygous for the C57BL/6-derived allele (AA; n = 42). ***<i>P</i><1.0×10⁻⁶ versus the A/J-derived allele, ANOVA followed by Tukey's test for multiple comparisons. The line within each box represents the median; upper and lower edges of each box are 75^th and 25^th percentiles, respectively; upper and lower bars indicate the highest and lowest values less than one interquartile range from the extremes of the box.</p

COVID-19 Host Genetics Initiative. A first update on mapping the human genetic architecture of COVID-19

The COVID-19 pandemic continues to pose a major public health threat, especially in countries with low vaccination rates. To better understand the biological underpinnings of SARS-CoV-2 infection and COVID-19 severity, we formed the COVID-19 Host Genetics Initiative1. Here we present a genome-wide association study meta-analysis of up to 125,584 cases and over 2.5 million control individuals across 60 studies from 25 countries, adding 11 genome-wide significant loci compared with those previously identified2. Genes at new loci, including SFTPD, MUC5B and ACE2, reveal compelling insights regarding disease susceptibility and severity.</p