Clinical Indication ID & Name
Holoprosencephaly
Test Group
Neurology
Specialties
Test code
R85.2
Test name
N/A
Target genes
Holoprosencephaly (78)
Test scope
n/a
Test method/ technology
WGS
Optimal Family Structure
n/a
Eligibility Criteria
Liveborn individuals with unexplained holoprosencephaly in whom a chromosomal cause is unlikely or has already been excluded by microarray or common aneuploidy testing .
Referrals for testing will be triaged by the Genomic Laboratory; testing should be targeted at those where a genetic or genomic diagnosis will guide management for the proband or family.
Where in Pathway
At presentation following chromosome microarray or common aneuploidy testing (which may have been prenatally through screening ) unless a chromosomal cause is deemed less likely and a broader testing approach is appropriate.
Commissioning group
Specialised
Overlapping idications
• R27 Paediatric disorders or R89 Ultra-rare and atypical monogenic disorders tests should be used in individuals with congenital malformations, dysmorphism or other complex or syndromic presentations • R26 Likely common aneuploidy • R28 Congenital malformation and dysmorphism syndromes – microarray
Address for samples/request forms
Genetics Laboratory
5th Floor Tower Wing
Guy’s Hospital
London
SE1 9RT
Contact with queries
Supporting documents
n/a
Education resources
n/a
Turn around times
All our turnaround times are listed on our specific turn around page https://southeastgenomics.nhs.uk/professionals/service-turn-around-times/
Request form download
Consent record
See consent guidance in test request form
Sample requirements
Sample Requirements Each sample must be sent labelled with 3 patient identifiers and must state the sample type clearly on the sample container. Sample Rejection Samples may be rejected for the following reasons: 1. Samples and request form do not show at least three identical patient identifiers 2. The sample is in the incorrect collection media 3. The request form is not sufficiently completed 4. The sample is not of sufficient volume 5. The sample is too old Sample Storage and Volume Required: 1. Peripheral blood in an EDTA tube: Adult and children 4 ml, Infants (0-2 years) 1 ml or a DNA sample (1-7µg of purified DNA). Where it is not possible to collect peripheral blood we will accept a saliva sample (please contact the lab for specific details). 2. Bone marrow sample in EDTA tube, cell count must be provided. 3. Cultured Fibroblasts in medium 4. Fresh tissue with at least 30% tumour cell content: Adequate sample sizes include 5mm x 5mm x 2mm tissue or 15mm x 2mm needle core biopsy. Multiple biopsies recommended if clinically feasible. Tissue should be embedded in OCT or preserved in RNA Later where appropriate 5. Extracted DNA , 1 μg to 7.2 μg depending on WGS pathway. Storage, sample packing and transportation: Blood and bone marrow samples should be stored at 4°C whenever possible and sent at room temperature via first-class post or courier. Tissue samples preserved in RNA Later can be shipped at room temperature, while fresh tissue samples must be shipped on ice/dry ice. All samples should arrive at the laboratory within 24 hours of collection. Patient/Clinician Instructions: N/A Factors affecting performance of test/interpretation of results: Clotted samples are unsuitable for DNA analysis. Blood Samples in incorrect anticoagulant tubes may be rejected.