Molecular Cytogenetics

Cytogenetics Website

Molecular Cytogenetics

Postnatal Section (Blood samples)

Regional Cytogenetics Department

St James’s Hospital

Leeds

LS9 7TF

Head of section: Steve Morris

Telephone: 0113 206 6566

Email: stephen.morris@leedsth.nhs.uk

FISH

Reason for Referral

•Microdeletion/duplication syndromes for family follow-up or if no DNA available for MLPA (eg Smith magenis syndrome, DiGeorge syndrome)

Telomere screening in cases not appropriate for MLPA (in conjunction with Clinical Genetics consultants).
• Haematology translocations.
• Other oncology probes.
• Aneuploidy screening (rapid post-natal testing eg Down syndrome).
• Internal referrals (Marker identification, abnormality confirmation).
• Paraffin sections from selected tumours.

MLPA microdeletion test

Reason for referral - query microdeletion (eg Smith Magenis, DiGeorge syndrome)

Syndromes tested

Please send 1ml blood in EDTA and 1ml lithium heparin for microdeletion testing. If there is insufficient blood for two samples please send lithium heparin in the first instance although this may compromise the tests perfomed.The following regions are tested using this kit:

Reporting of results

Multiple syndromes will be assayed simultaneously; therefore an unexpected result may be obtained. In all abnormal cases, genetic counselling will be recommended.

General requests for microdeletion MLPA testing without clinical details will not be processed.

MLPA microdeletion studies.

Requirements: 1-2 mls (minimum) of peripheral blood in a lithium heparin tube (green or orange top) AND 1-2 mls of peripheral blood in a EDTA tube (purple top) & referral card completed with Name, NHS no., d.o.b. address and comprehensive list of clinical details.

For MLPA only, a karyotype requires Lithium Heparin tubes (orange or green top)

MLPA sub-telomere studies.

Referrals for this test must be arranged through the Clinical Genetics Department, Chapel Allerton Hospital, Leeds.

Please note this test will only detect unbalanced rearrangements.

Please note that FISH testing might be performed if the sample received is sub-optimal (sent without an EDTA sample or too small (<1.0mls)) or where it is considered by the lab to be the most cost effective approach.

Summary of Microdeletion syndromes tested for by the P245 MLPA microdeletion kit

Loci Tested	Associated Microdeletion/duplication Syndrome
1p36.33	1p36 Deletion syndrome
2p16.1	2p16 Deletion syndrome
3q29	3q29 Deletion syndrome
4p16.3	Wolf-Hirschhorn syndrome
5p15.33	Cri-du-Chat syndrome
5q35.3	SOTOS syndrome
7q11.2	Williams syndrome/7q11.23 duplication
8p23.1	8p23 Deletion syndrome
8q24	Langer-Gideon syndrome
9q22.33	9q22 Deletion syndrome
10p14	DiGeorge syndrome region 2
11p13	WAGR syndrome
15q11.2	Prader-Willi/Angelmans syndrome
15q24.1	15q24 Deletion syndrome
16p13.3	Rubinstein-Taybi syndrome
17p11.2	Smith-Magenis syndrome/17p11.2 duplication
17p13.3	Miller-Dieker syndrome
17q11.2	NF1 Deletion
17q21.31	17q21 Deletion syndrome
22q11.2	DiGeorge syndrome/22q11.2 duplication
22q13.3	Phelan-McDermid syndrome
Xq28	MECP2 duplication syndrome

Technical details of P245 kit (Base positions based on Human GRCh37 Assembly hg19)

Reporting of Results

• Molecular cytogenetic results are usually reported with routine analysis, this may lead to some delays in reporting.

• Unless stated, reports are based on the analysis of metaphase cells.

• In the case of complex results, the interpretation and implications will be discussed with the referring clinician.

• Surplus fixed material from FISH cases is usually saved for 2 years. If follow up or further studies are required for diagnostic purposes, it may be possible to do these without a repeat sample.

Samples should be addressed to:

Cytogenetics Unit

St James's Hospital

Beckett Street

Leeds

LS9 7TF

Available FISH tests

PDF version of FISH guide

PDF version of MLPA microdeletion user manual

Last Updated 7.2.12