Biochemical Genetics

Transcription

1 Biochemical Genetics Laboratory Handbook 20010/11 Block 20 St James s Hospital Beckett Street Leeds LS9 7TF Introduction The Biochemical Genetics service is comprised of two regional laboratories, screening and metabolic. The services provided by these laboratories are detailed below. Biochemical Genetics is a sub division of the Department of Specialised Laboratory Medicine, Leeds Teaching Hospitals Trust. It is located at the St James s University Hospital site. Samples and mail for Biochemical Genetics should include reference to Block 20. CPA Status Accredited Contacts: Dr Mick Henderson, Consultant Clinical Scientist, Laboratory Director Neonatal Screening Screening Office, main enquiry service mick.henderson@leedsth.nhs.uk Dr Leonie Shapiro, Principal Clinical Scientist leonie.shapiro@leedsth.nhs.uk Dr Anthea Patterson, Principal Clinical Scientist anthea.patterson@leedsth.nhs.uk Mr Timothy Williams, Laboratory and Clinical Systems Manager, timothy.williams@leedsth.nhs.uk Dr Sally Kinsey, Consultant Haematologist, sally.kinsey@leedsth.nhs.uk Mrs Lisa Farrar, Antenatal & Newborn Haemoglobinopathy Screening Coordinator lisa.farrar@leedsth.nhs.uk 2 of 9

2 Antenatal Screening Mr Daniel Herrera, Principal Clinical Scientist Metabolic Laboratory Contacts: Laboratory enquiries, Mr Colin Evans, Principal Clinical Scientist Miss Janet Mitchell, Senior Biomedical Scientist Mr Ian Sherratt, Senior Biomedical Scientist Mrs Barbara Waddell, Senior Biomedical Scientist Mr Robert Barski, senior clinical scientist, Secretarial Office Diane Young of 9 Neonatal Screening Service Area Covered This laboratory provides the neonatal screening service for all births in the following PCTs: North Yorkshire and York (except Hambleton/Richmondshire), Bradford and Airedale Teaching, Leeds, East Riding of Yorkshire, Hull Teaching, Calderdale, Kirklees, Wakefield and also Jersey in the Channel Islands. Sample type Heelprick bloodspots should be collected between day 5 and 7 onto the single leafed screening card supplied by Whatman Schleicher and Schuell product no They must be sent on the day of collection, by first class post, to the screening laboratory. Analytical Programme The profile of tests performed and the investigation and follow up protocols used by this laboratory adhere to national policy as defined by The UK Newborn Programme Centre and the NHS Sickle Cell and Thalassaemia Screening Programme In addition three metabolic conditions with a high local prevalence are included in the profile. All samples received are tested for phenylalanine (PKU), tyrosine and succinyl acetone if tyr raised (tyr type 1), leucine (Maple syrup urine disease), methionine (homocystinuria), thyroid stimulating hormone (congenital hypothyroidism), immuno reactive trypsin (cystic fibrosis), octanoyl carnitine (medium chain acyl CoA dehydrogenase deficiency) and haemoglobin variants (sickle disease and thalasseamia). Reporting of Results Copies of all reports are sent by first class post to the relevant Child Health Record Department. CHRDs record the results and send a copy of the report to the relevant Health Visitor or General Practitioner so that it can be included in the individual child s health record. Action is taken immediately on positive results according to national and locally agreed protocols. 4 of 9

3 Retention of Cards Unused material remaining on the bloodspot cards are retained in a secure store indefinitely. These may be made available for further clinical tests, but only after consultation between a requesting consultant paediatrician and the laboratory Director, and only with the consent of the parent. External Quality Assurance for bloodspot assays NEQAS; Phenylalanine TSH Haemoglobin CDC, Atlanta; IRT Acyl carnitines, quantitative Amino acids quantitative MCADD National Collaborative Project; MCADD metabolites Down Syndrome TSH requests The screening laboratory provides a service to facilitate regular monitoring of children with Downs syndrome for hypothyroidism. These children tend to have a phobia of needles making venepuncture difficult, but they are known to be at increased risk of developing hypothyroidism. TSH is measured in dried bloodspots. The cards sent to the laboratory must be clearly identified as Downs TSH Monitoring and indicate the address for results to be reported. Antenatal Service The screening laboratory provides biochemical analyses on blood samples taken during the first and second trimester of pregnancy and risk calculation for Down s syndrome. The reports generated are sent as pdf files by to screening coordinators using secure NHS net accounts. Tests: First trimester: free beta human chorionic gonadotrophin, pregnancy associated plasma protein A Second Trimester: alpha feto protein, free beta human chorionic gonadotrophin, unconjugated estriol. 5 of 9 Metabolic Laboratory Service Test Repertoire Analyte Sample Type Sample Requirements Acyl carnitines bloodspots Min 2 spots Mark bloodspot card clearly with request Amino acids* Plasma, lithium hep Min 0.5mL Amino acids* Urine, plain Min 1.0 ml Amino acids CSF Min 200 µl Ammonia Plasma, lithium hep Min 0.5 ml To reach laboratory within 30 mins Biotinidase serum Min 0.5mL To reach laboratory within 24hrs or be stored and sent frozen Galactose 1 phosphate uridyl transferase Whole blood, lithium hep Min 200 µ/l Invalid if baby recently transfused Homocysteine, total Plasma, EDTA Min 0.5mL, separate within 30 min venepuncture 6 of 9

4 HVA and HMMA Spot urine, 25mL plain bottle containing 1.0mL 4M HCl Lactate Plasma, fluoride oxalate Methyl malonic acid Urine, plain Mucopolysaccharides Urine, plain Oligosaccharides Urine, plain Organic acids Urine, plain Orotic acid Urine, plain Sugars, mono and Urine, plain disaccharides Sweat chloride Sweat collected under controlled conditions following pilocarpine stimulation White cell cystine Whole blood, lithium hep Min 5mL. Urine should be collected in the morning, before any meals but not the first sample passed after waking. Min 0.5 ml By prior arrangement with the laboratory Min 4 ml, to reach laboratory within 24 hrs Amino acid reports are provided as qualitative or quantitative depending on the nature of the request. Specific and rare amino acids can be requested, e.g. urine phosphoethanolamine, sulphocysteine 7 of 9 Use of the metabolic service Samples sent on a routine basis for metabolic investigations are analysed and reported within one working week. Urgent analyses must be organised in advance by telephone to one of the points of contact listed. External Quality Assurance This laboratory has a strong record not only of participating in EQA but also being involved in its organisation. The laboratory formerly initiated and organised the Yorkshire regional metabolic testing scheme in urine samples (SJQA). This was amalgamated with the other existing regional schemes to create the NEQAS urine amino acid scheme. Mr Colin Evans is a member of the NEQAS specialist advisory group for paediatric EQA schemes. Dr Mick Henderson is a Board member and specialist scientific advisor to ERNDIM. Schemes that the laboratory participates in: ERNDIM, European; Urine metabolic proficiency scheme Urine organic acids Plasma amino acids, quantitative Total leukocyte cystine Bloodspot acyl carnitines NEQAS, Birmingham; urine amino acids, qualitative urine orotic acid plasma total homocysteine plasma phenylalanine and tyrosine (PKU monitoring) plasma branched chain aa (MSUD monitoring) sweat test analysis amino acids, interpretative Manchester, Willink; Urine mucopolysaccharides WEQAS; total homocysteine 8 of 9

5 Costs The current tariff is available on request from Dr Henderson Investigation Guidelines A useful set of investigation guidelines can be downloaded from the website of the MetBioNet at In addition to these the laboratory can provide copies of locally agreed protocols for investigating sudden unexpected death in infancy and acute metabolic emergencies. Training and Education The biochemical genetics laboratories are regarded as a regional training resource and welcome visits and periods of study by staff from other laboratories. Senior staff from the laboratories participate in and support a wide range of national and regional, multi disciplinary, training and teaching programmes. 9 of 9