Medical genetics, Cytogenetics Techniques and diagnostic methodology

Module Cytogenetics Techniques

At the end of the course the student should be able to:

-understand the structure of the human genome and know the main mechanisms that may disrupt its architecture. To know the main techniques in the field of the classical and molecular cytogenetics, and the use of  NGS techniques  in order to identify the structural anomalies of the genome both in pre and postnatal settings.

 Objectives according to the Dublin Descriptors

1) Knowledge and understanding

By the end of the course, students know and understand:

• the structure of the human genome, chromosomes and chromosome morphology;

• the main mechanisms affecting genomic integrity (non-disjunction, structural rearrangements, CNVs);

• principles, indications and limitations of the main methods used in pre- and post-natal genetic diagnosis: karyotyping/banding, FISH, array-CGH, SNP-array, confirmatory methods (MLPA, Real-Time PCR), and the basic principles of NGS/WGS for detecting structural variants.

2) Applying knowledge and understanding

Students are able to:

• choose the most appropriate technique according to the diagnostic question (locus-specific vs genome-wide; first-tier testing vs confirmation);

• interpret, at an introductory level, common cytogenetic findings (aneuploidies, deletions/duplications, translocations/inversions);

• understand the essential principles of array signal analysis and apply general reporting/validation criteria.

3) Making judgements

Students develop basic independent judgement to:

• evaluate the suitability and limitations of cytogenetic techniques (resolution, sensitivity/specificity, sample requirements and controls);

• integrate cytogenetic results with the clinical context to provide a preliminary interpretation;

• recognise general implications of balanced and unbalanced rearrangements (e.g., reproductive risk) and identify when further investigations are required.

4) Communication skills

Students are able to:

• describe, using appropriate technical terminology, principles, indications and differences between classical and molecular cytogenetics;

• communicate clearly the diagnostic meaning of karyotyping, FISH, arrays and confirmation strategies;

• present orally, in a coherent and structured way, a cytogenetic diagnostic workflow by connecting different topics from the syllabus.

5) Learning skills

Students are able to:

• consolidate course contents independently using textbooks and lecture notes;

• integrate basic cell biology/genetics knowledge with cytogenetic tools to address standard questions;

• maintain an introductory level of updating on the use of NGS/WGS and genome-wide approaches for structural variant detection in genetic diagnostics.

Frontal teaching.

Should teaching be carried out in mixed mode or remotely, it may be necessary to introduce changes with respect to previous statements, in line with the programme planned and outlined in the syllabus.

 • The double strand structure

• Chromosome structure and their morphology

• Classical Cytogenetics  and banding techniques

• The karyotype and its diagnostic indications

• FISH analysis

• Array-CGH and pathogenic mechanisms  of the CNVs

• Statistical analysis of array signals

• SNP-array

• Validation methods of genomic imbalances  (MLPA, RealTime-PCR)

• The next generation sequencing approach

• The use of whole genome sequencing for the identification of genomic structural variants

1.Testo Atlante di Citogenetica Umana (Ventruto, Sacco, Lonardo)

2. Computational exome e genome analysis CRC press 2018

3. Teacher's documentation