Our laboratory was founded in 2003. Since that time we have continued to expand both in terms of personnel and equipment as well as the spectrum of performed methods.

Due to the quality of the instruments in our laboratory we are able to perform molecular genetic examinations in accordance with the latest diagnostic trends. We carry out detection of known mutations using PCR, or Real Time PCR and detection of mutations using direct sequencing to diagnose monogenic hereditary diseases. We also perform quick diagnostics of the most common aneuploidies from native amniotic fluid using multiplex QF PCR. We ensure transfer of the samples for DNA examination of various hereditary diseases to various departments in the Czech Republic, and if needed abroad.

We can offer determination of paternity (or maternity, parity) including expert opinions. The expert opinions are done at the request of the court, authorities involved in criminal proceedings and private persons.

Our laboratory is accredited according to ČSN EN ISO 15189.

We successfully take part in annual external quality audits.

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List of performed methods

QF-PCR (Quantitative Fluorescence Polymerase Chain Reaction) is a rapid diagnostic method detecting the most common aneuploidies and uniparental disomy of autosomes (13, 18, 21, 15, 16, 22) and sex chromosomes (X, Y). The analysis consists of detection of specific STR loci via PCR followed by fragmentation analysis using capillary electrophoresis.

Molecular-genetic examination using QF-PCR allows diagnosis of aneuploid genetic conditions including the Down, Edwards, Patau, Klinefelter, Turner, Jacob (supermale, XYY), triple X (superfemale, XXX) and polyploidy syndromes.

Examination of aneuploidies can be performed from the amniotic fluid, chorionic villi, fetal blood, and aborted fetal tissue. It is followed by cytogenetic examination of all chromosomes.

Indications for testing include: a positive atypical or borderline screening of first and second trimester, overall genetic risk to the fetus above 10%, abnormal ultrasound findings, combination of multiple risk factors

Cystic fibrosis (CF, mucoviscidosis) is a multisystem autosomal recessive genetic disorder whose classical form is manifested by respiratory and lung disease, pancreatic exocrine insufficiency, high concentration of electrolytes in sweat, and male reproductive disorder. The incidence of CF is 1:4500 in the Czech population, i.e. the carrier frequency is 1:34 (Votava F. et al., 2014). Cystic fibrosis is caused by mutations in the CFTR gene.

Our laboratory carries out an analysis that can detect 36 mutations and determine polymorphisms in intron 8 (Tn variants) of the CFTR gene. Mutations included in the test represent 91% of all causal CTFR mutations in the Czech population. If these mutations are not detected (negative CFTR test), the probability of carrying another mutation in the CFTR gene is reduced to 1:278 (0.36%). The test is suitable for both, the identification of asymptomatic carriers (heterozygotes) and the molecular-genetic diagnosis of affected individuals (homozygotes).

Indications for testing: subjects with CF symptoms, relatives of a patient suffering from CF and having detected CFTR mutations, couples where one partner carries a causal heterozygous mutation in the CFTR gene (testing before conception or during pregnancy), couples where both partners carry a causal heterozygous mutation in the CFTR gene (prenatal diagnosis), adult males with fertility disorders, preconception testing, gamete donors

Analysis of the AZF (azoospermia factor) region, which is located on the long arm of the Y chromosome (Yq) and is subdivided into AZFa, AZFb, and AZFc. Genes in the AZF region function in spermatogenesis and are essential for male reproduction. Depending on which of the azoospermia factors is absent, men develop oligozoospermia (reduced sperm count in the ejaculate) to azoospermia (absence of sperm in the ejaculate). Examination of sequence-tagged site (STS) markers on Yq detects about 90% of deletions in AZF regions.

Indications for testing include: male fertility disorder - poor spermiogram parameters

The aim of the examination is to detect the c.657-661del mutation, a deletion of five nucleotides, in the NBN gene. This mutation in the homozygous state causes the Nijmegen breakage syndrome (NBS), also known as Seemanova syndrome. NBS is a rare autosomal recessive DNA-repair disorder. It is a chromosome instability syndrome manifested by microcephaly, growth retardation, immunodeficiency, and predisposition to malignancy. Higher incidence of malignancies also affects heterozygous carriers. Patients with NBS are hypersensitive to ionizing radiation. The mutation c.657-661del is more common in the Slavic population, the frequency of carriers is 1:100-150.

Indications for testing: suitable for patients with clinical manifestations including microcephaly, chromosomal instability, growth retardation, increased frequency of malignancies in family history (especially lymphomas and leukemia), decreased serum IgG and IgA levels.

Haemochromatosis is an autosomal recessive disorder of iron storage that results in aberrant iron deposition in parenchymal cells. As the disease progresses, it leads to extensive tissue damage, diabetes mellitus, liver cirrhosis, hepatocellular carcinoma, heart failure, arthritis, and skin pigmentation. First symptoms often appear between the age of 40 and 50.

The test detects the most common mutations c.845G>A (C282Y) and c.187C>G (H63D) in the human HFE gene using allele-specific PCR. The examination is suitable for both, the identification of asymptomatic carriers (heterozygotes) and the molecular-genetic diagnosis of affected individuals (homozygotes).

Indications for testing: liver fibrosis or cirrhosis, cardiomyopathy, pancreopathy, diabetes, arthropathy, skin pigmentation.

Thrombophilia is a tendency to enhanced blood clotting, i.e. an increased risk of blood clots (thrombi) that can lead to partial or complete closure of blood vessels, most commonly in the lower limbs. Part of the clot may detach and, carried by the venous system, may pass through the heart and close one of the pulmonary arteries, resulting in the pulmonary embolism. We examine two mutations, one in the F5 gene, the other in the F2 gene. These genes encode the coagulation factors V and II, respectively, that are important in the process of blood clotting. The G1691A mutation in the F5 gene is called Leiden (FV Leiden). In the Czech population, 5-10% of carriers of this mutation are heterozygous (one allele mutated), which increases the risk of thromboembolic disease by about seven times. In the case of homozygous individuals (both alleles mutated) the risk is approximately twenty times higher. The other mutation occurs in the F2 gene that codes for the factor II (prothrombin). Heterozygotes carrying this mutation represent about 2-3% in the population with the risk to develop thrombosis being about three times higher. It is up to eighteen times higher in the homozygotes.

Indications for testing:

  • venous thrombosis (embolism) in an individual under 50 years of age
  • thrombosis occurring in an unusual body part
  • thromboembolic disease in a patient with a family history of thromboembolism
  • thromboembolic disease in a patient with a family history of thromboembolism
  • patient prior to scheduled surgery with a family history of thromboembolism
  • a patient with recurrent miscarriages in the second or third trimester without a clear cause
  • indication by a clinical haematologist
Congenital hearing disorders occur in about 1 in 1000 newborns, and about half of them have a genetic cause. Mostly, it is an autosomal recessive nonsyndromic (not associated with other symptoms) hearing loss. We examine prevalent mutations c.35delG (G12fs) and c.71G>A (W24X) in the GJB2 gene encoding connexin 26, which are the most common cause of nonsyndromic hearing loss. The examination is suitable for both, the identification of asymptomatic hearing carriers (heterozygotes) and the molecular-genetic diagnosis of affected individuals (homozygotes).

Indications for testing:

  • prelingual hearing loss
  • prelingual hearing loss in the family
  • congenital hearing loss prior to cochlear implantation
  • the presence of the mutation in consanguineous partners, or in newborns of incestuous relationships
  • hearing relatives in families where the mutation has already been detected
Celiac disease is an autoimmune disease caused by intolerance to gluten, which is a protein component of wheat, rye, and barley. The disease causes inflammation of the mucous membrane of the small intestine and destruction of villi and microvilli. The most common symptoms are abdominal pain, flatulence, diarrhea, sporadically constipation or vomiting, loss of appetite, and weight loss. In young children, a heaving tummy and growth disorders can often be observed.

The test detects HLA alleles predisposing to celiac disease. Examined alleles occur in more than 99% of patients with celiac disease and in 20% of healthy controls. The presence of predisposing alleles increases the risk of celiac disease fifty times compared to the general population.

Indications for testing:

  • failure to thrive
  • indigestion
  • occurrence of celiac disease in the family
  • anemia of unknown origin
Ankylosing spondylitis (AS; Bechterew's disease) is a chronic inflammatory disease of the vertebrae. The exact cause of AS is unclear, but it has been found that more than 95% (in the Caucasian population) of patients with AS have the HLA-B27 antigen. The incidence of the HLA-B27 allele in Caucasians is about 8%. People with the HLA-B27 antigen are up to 300 times more likely to develop AS than those who do not have the antigen. However, the presence of the HLA-B27 antigen does not mean that the disease will manifest, it only represents an increased risk.

The test detects the presence of the HLA-B27 allele. It is not recommended to use this examination to diagnose the ankylosing spondylitis in an asymptomatic population. The positive test (presence of HLA-B27 allele) indicates higher probability of AS occurrence, i.e. disease susceptibility, in a symptomatic individual. On the other hand, the negative test (absence of the HLA-B27 allele) may help rule out the AS in a clinically unclear patient.

Indications for testing:
Back pain, chronic pain or stiffness of the lower spine, reduced flexibility of the spine, chest pain during deep breathing, chronic fatigue, inflammation of the iris and ciliary body (iridocyclitis), less frequent symptoms: joint inflammation, pulmonary fibrosis, detachment of the nails from the nail bed.

Fragile X syndrome (FXS) is an X-linked disorder manifested by mental retardation with possible dysmorphic features (elongated face with protruding chin and large protruding ears). The syndrome is caused by a dynamic mutation, the expansion of CGG trinucleotides in the 5 ́ untranslated region of the FMR1 gene. The number of repeats varies from the normal number of repeats, through intermediate mutation, premutation to full mutation.

Carriers of the premutation are not affected by intellectual disability, but the premutation causes presenile tremor and premature ovarian failure in women, thus exhibiting a low penetrance (in about 20% of female carriers of the premutation). Premutations are unstable during meiosis or early embryogenesis and if they are transmitted by a woman, there is a risk of expansion of CGG-repeat to the full mutation. On the other hand, premutations transmitted by males rarely expand into the full mutation. Intellectual disability caused by the full mutation mainly affects men, but the disease can also manifest itself in women. Approximately half of the female carriers of the full mutation have mild to moderate intellectual disability.

During the PCR test, we determine the number of CGG repeats in the FMR1 gene.

Indications for testing:

  • psychomotor retardation, autism in personal or family history
  • premature ovarian failure
  • presenile tremor in men
Gilbert syndrome (GS) is a lifelong autosomal recessive inherited disorder of the bilirubin (bile pigment) metabolism in the blood. It is caused by disrupted function of UDP-glycosyltransferase 1A1 (UGT1A1), reduced to 20-30% in affected homozygotes. It is most often manifested by mild hyperbilirubinaemia without signs of liver disease or hyperhemolysis. The disease is considered to be of minor importance. The most common mutation causing GS (over 90% of cases) is a 2-bp insertion (TA) in the TATA element of the promoter region of the UGT1A1 gene, which results in (TA)7 instead of (TA)6.

During the examination, we detect the number of TA repeats in the TATA element and if a homozygous result of 7TA/7TA is found, we confirm the Gilbert syndrome.

Indications for testing:

  • isolated mild hyperbilirubinemia (suspected GS)
  • relatives with confirmed GS
  • before taking irinotecan (GS represents a pharmacogenetic risk factor for irinotecan toxicity)
As all mammals, humans' ability to digest lactose is greatest in infancy and decreases with age. An adult produces only one-tenth of lactase compared to an infant, and most people by the age of 60 do not digest lactose at all. An estimated 75-80% of the world's population is lactose intolerant in adulthood. The most common symptoms are lactose indigestion, flatulence, abdominal distension and diarrhoea. Lactose intolerance varies between ethnic groups, with around 30% in the European population. We examine the -13910C>T variant in the promoter region of the LCT gene.

The examination is suitable for both, the identification of asymptomatic carriers (heterozygotes) and the molecular-genetic diagnosis of affected individuals (homozygotes).

Indications for testing:

  • gastrointestinal upset after eating foods containing lactose
  • differentiation of the primary type of lactase deficiency from the secondary type
  • pathological lactose tolerance test or positive H2 breath test
  • osteoporosis
Non-invasive prenatal testing (NIPT) is an examination of the most common aneuploidies of the fetus from the mother's blood. Cell-free DNA (a mixture of cell-free maternal and fetal DNA) isolated from plasma is analysed. We use the Panorama test (Natera), based on target SNP sequencing, which allows us to distinguish fetal and maternal cell-free DNA. The Panorama test shows high sensitivity for trisomy of chromosome 21 (99%), 13 (99%), 18 (96.4%) and sex chromosomes (100%), as well as for monosomy of the X chromosome (92.9%). In addition, it can detect vanishing twin syndrome, triploidy, and aneuploidies of chromosomes 13, 18, 21 in twin and donated oocyte pregnancies.

Indications for testing:

  • increased genetic risk of chromosomal aberration for the fetus (chromosomes 21,18, 13, X, Y)
  • normal ultrasound findings while positive/borderline/atypical prenatal screening
  • increased risk of complications when performing invasive diagnostics (CVS/AMC) because of higher genetic risk
  • older age of pregnant woman (over 38 years)
  • pregnancy via IVF, dysfertility, or sterility treatment
Only a small proportion of tumors (5-10%) are inherited, i.e. they are hereditary tumor syndromes.

Hereditary cancers arise as a result of inherited mutations (disorders of genetic information in the DNA) of tumor predisposing genes, of which several hundred are known. The causal mutation is passed down from generation to generation in the affected family. The offspring can inherit it from the carrier parent in half of the cases. The presence of the causal mutation significantly increases the likelihood of developing cancer.

Early analysis of hereditary cancer predisposition is of particular importance for high-risk individuals and allows the inclusion of mutation carriers in preventive monitoring programs and consideration of possible prophylactic surgeries. The most common hereditary forms of tumors are breast, ovarian and colon tumors.

Hereditary breast and/or ovarian cancer syndrome is an autosomal dominant syndrome with incomplete penetrance. It is caused by causal (pathogenic) mutations, especially in tumor suppressor genes BRCA1 or BRCA2. In addition to the BRCA1,2 genes, the TP53, STK11, CDH1, PTEN, PALB2 genes are considered to be high-risk, while the ATM, CHEK2, NBN genes are considered to be at medium risk in connection with breast cancer. In ovarian cancer, the genes causal for Lynch syndrome (MLH1, MSH2, MSH6, PMS2) are high-risk, as well as the genes BRIP1, RAD51C and RAD51D.

Colon tumors can be divided into non-polyposis – Lynch syndrome (genes MLH1, MSH2, MSH6, PMS2, EPCAM, MUTYH) and adenomatous polyposis – FAP (APC gene).

In addition to breast, ovarian and intestinal tumors, heredity can also apply to tumors of the stomach, skin, pancreas, kidneys, and others.

Mutational analysis/screening of these genes allows confirmation of the genetic background of cancer development in affected individuals and subsequent predictive testing of their biological relatives. Asymptomatic carriers of the mutation are included in a follow-up program, which serves for prevention and early detection of cancer. For the mutation analysis we use the Czecanca panel (Czech cancer panel for clinical application), which was developed by the group of Doc. MUDr. Kleibl from the Institute of Biochemistry and Experimental Oncology of the 1st Faculty of Medicine of Charles University in Prague. The panel contains 226 target genes associated with hereditary malignancies that are analysed using Next Generation Sequencing (NGS). It includes known predisposing genes (approx. 69 genes) whose mutations cause hereditary cancers (e.g. ATM, APC, BARD1, BRCA1, BRCA2, BRIP1, CDH1, CHEK2, EPCAM, MLH1, MSH2, MSH6, MUTYH, NBN, PALB2, PMS2, PTEN, RAD50, RAD51C, RAD51D, STK11, TP53, CDKN2A, CDK4 etc). Other genes included in the panel represent candidate genes for preclinical studies within the Czech population.

Indications for testing:

  • cancer at an unusually young age
  • people with multiple types of cancer
  • occurrence of bilateral tumors in paired organs
  • recurrence of the same type of cancer in a family history (e.g. breast or colorectal cancer)
  • combination of certain types of tumors (breast and ovarian cancer, colon, and uterine cancer) in close relatives, especially those with early onset of the disease
Spinal muscular atrophy (SMA) is the second most common cause of death in children from autosomal recessive disorders (incidence 1 per 10,000 live births). The frequency of heterozygotes, i.e. healthy carriers of the disease is 1:47 in the population.

SMA is an autosomal recessive neuromuscular disease characterized by degeneration of the spinal horns and caused by a mutation in the SMN1 gene. More than 95% of patients carry a homozygous (biallelic) deletion of SMN1. In addition to the SMN1 gene, the highly homologous pseudogene SMN2 is located on the same chromosome (chromosome 5). Most of SMN2 transcripts lack exon 7 due to the 840C>T substitution. The SMN2 protein cannot prevent SMA, however it can mitigate its phenotype. Determining the number of copies of the SMN2 gene is important for SMA patients because the more copies a patient has, the milder the symptoms of the disease.

The examination is performed using the MLPA method that detects large deletions and duplications. We determine the copy number of exon 7 and 8 in both the SMN1 gene and the SMN2 pseudogene.

Indications for testing:

  • gamete donors
  • preconception examination
  • individuals with neuromuscular disease
  • families with SMA and relatives of already diagnosed SMA carriers