Variable X-chromosome inactivation and enlargement of pericentral glutamine synthetase zones in the liver of heterozygous females with OTC deficiency

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11110%2F18%3A10377017" target="_blank" >RIV/00216208:11110/18:10377017 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/00023001:_____/18:00076944 RIV/00064165:_____/18:10377017

Výsledek na webu

<a href="https://doi.org/10.1007/s00428-018-2345-x" target="_blank" >https://doi.org/10.1007/s00428-018-2345-x</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1007/s00428-018-2345-x" target="_blank" >10.1007/s00428-018-2345-x</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Variable X-chromosome inactivation and enlargement of pericentral glutamine synthetase zones in the liver of heterozygous females with OTC deficiency

Popis výsledku v původním jazyce

Ornithine transcarbamylase (OTC) deficiency is an X-linked disorder that causes recurrent and life-threatening episodes of hyperammonemia. The clinical picture in heterozygous females is highly diverse and derives from the genotype and the degree of inactivation of the mutated X chromosome in hepatocytes. Here, we describe molecular genetic, biochemical, and histopathological findings in the livers explanted from two female patients with late-onset OTC deficiency. Analysis of X-inactivation ratios by DNA methylation-based assays showed remarkable intra-organ variation ranging from 46:54 to 82:18 (average 70:30, n = 37), in favor of the active X chromosome carrying the mutation c.583G &gt; C (p.G195R), in the first patient and from 75:25 to 90:10 (average 82:18, n = 20) in favor of the active X chromosome carrying the splicing mutation c.663+1G &gt; A in the second patient. The X-inactivation ratios in liver samples correlated highly with the proportions of OTC-positive hepatocytes calculated from high-resolution image analyses of the immunohistochemically detected OTC in frozen sections that was performed on total area &gt; 5 cm(2). X-inactivation ratios in blood in both female patients corresponded to the lower limit of the liver values. Our data indicate that the proportion of about 20-30% of hepatocytes expressing the functional OTC protein is not sufficient to maintain metabolic stability. X-inactivation ratios assessed in liver biopsies taken from heterozygous females with X-linked disorders should not be considered representative of the whole liver.

Název v anglickém jazyce

Variable X-chromosome inactivation and enlargement of pericentral glutamine synthetase zones in the liver of heterozygous females with OTC deficiency

Popis výsledku anglicky

Ornithine transcarbamylase (OTC) deficiency is an X-linked disorder that causes recurrent and life-threatening episodes of hyperammonemia. The clinical picture in heterozygous females is highly diverse and derives from the genotype and the degree of inactivation of the mutated X chromosome in hepatocytes. Here, we describe molecular genetic, biochemical, and histopathological findings in the livers explanted from two female patients with late-onset OTC deficiency. Analysis of X-inactivation ratios by DNA methylation-based assays showed remarkable intra-organ variation ranging from 46:54 to 82:18 (average 70:30, n = 37), in favor of the active X chromosome carrying the mutation c.583G &gt; C (p.G195R), in the first patient and from 75:25 to 90:10 (average 82:18, n = 20) in favor of the active X chromosome carrying the splicing mutation c.663+1G &gt; A in the second patient. The X-inactivation ratios in liver samples correlated highly with the proportions of OTC-positive hepatocytes calculated from high-resolution image analyses of the immunohistochemically detected OTC in frozen sections that was performed on total area &gt; 5 cm(2). X-inactivation ratios in blood in both female patients corresponded to the lower limit of the liver values. Our data indicate that the proportion of about 20-30% of hepatocytes expressing the functional OTC protein is not sufficient to maintain metabolic stability. X-inactivation ratios assessed in liver biopsies taken from heterozygous females with X-linked disorders should not be considered representative of the whole liver.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10600 - Biological sciences

Projekt

—

Návaznosti

S - Specificky vyzkum na vysokych skolach<br>I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2018

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Virchows Archiv

ISSN

0945-6317

e-ISSN

—

Svazek periodika

472

Číslo periodika v rámci svazku

6

Stát vydavatele periodika

DE - Spolková republika Německo

Počet stran výsledku

11

Strana od-do

1029-1039

Kód UT WoS článku

000435410300017

EID výsledku v databázi Scopus

2-s2.0-85045036807