Intended purpose
The SALSA MLPA Probemix P064 Microdeletion Syndromes-1B is an in vitro diagnostic (IVD)¹ or research use only (RUO) semi-quantitative assay² for the detection of a distinct subset of recurrent microdeletions and microduplications (mentioned in the table below) in genomic DNA isolated from human peripheral whole blood, buccal swabs, (un)cultured amniotic fluid obtained in week 16 of the pregnancy or later and free from blood contamination, (un)cultured chorionic villi free from maternal contamination, or foetal blood specimens. P064 Microdeletion Syndromes-1B is intended to confirm a potential cause for and clinical diagnosis of developmental delay, intellectual disability and/or congenital anomalies.

This probemix has a limited number of probes for each specific chromosomal region and will therefore not detect all possible causes of the syndromes included. Copy number variations (CNVs) detected with the P064 Microdeletion Syndromes-1B probemix must be confirmed by a designated MLPA follow-up probemix or another technique.
Assay results are intended to be used in conjunction with other clinical and diagnostic findings, consistent with professional standards of practice, including confirmation by alternative methods, parental evaluation, clinical genetic evaluation, and counselling, as appropriate. The results of this test should be interpreted by a clinical molecular geneticist or equivalent.

This device is not intended to be used for standalone diagnostic purposes, pre-implantation testing, population screening, or for the detection of, or screening for, acquired or somatic genetic aberrations.

Please note that this probemix is for in vitro diagnostic (IVD) use in the countries specified at the end of this product description. In all other countries, the product is for research use only (RUO).
²To be used in combination with a SALSA MLPA Reagent Kit and Coffalyser.Net analysis software.

Syndromes that can be detected by the P064 probemix
Syndrome	Genetic locus	OMIM	Number of probes
1p36 deletion syndrome	1p36	607872	4
Wolf-Hirschhorn syndrome	4p16.3	194190	4
Cri-du-Chat syndrome	5p15	123450	5
Sotos syndrome	5q35.3	117550	3
Saethre-Chotzen syndrome	7p21.1	101400	2
Williams-Beuren syndrome	7q11.23	194050	3
Williams-Beuren duplication syndrome	7q11.23	609757
Trichorhinophalangeal syndrome type 2	8q24.11-q24.13	150230	3
WAGR syndrome	11p13	194072	3
Prader-Willi syndrome	15q11.2	176270	4
Angelman syndrome	15q11.2	105830
Rubinstein-Taybi syndrome	16p13.3	180849	2
Miller-Dieker syndrome	17p13.3	247200	4
Lissencephaly-1	17p13.3	607432
Smith-Magenis syndrome	17p11.2	182290	4
Potocki-Lupski syndrome	17p11.2	610883
Alagille syndrome	20p12.2	118450	2
DiGeorge syndrome	22q11.21	188400	7
22q11.2 microduplication syndrome	22q11.2	608363
Phelan-McDermid syndrome	22q13	606232	2

Clinical background
Microdeletion and microduplication syndromes are defined as a group of clinically recognisable disorders characterised by a small (< 5 Mb) deletion or duplication of a chromosomal segment spanning one or multiple disease genes. The phenotype is the result of haploinsufficiency or overexpression of specific genes in the critical interval. Clinically well described syndromes, for which the involvement of multiple disease genes has been established or is strongly suspected, include DiGeorge syndrome (22q11 microdeletion), Williams-Beuren syndrome (7q11 microdeletion), Smith-Magenis Syndrome (17p microdeletion) and many more. Most patients with microdeletion/microduplication syndromes present with intellectual disability (ID), developmental delay (DD), congenital abnormalities and/or dysmorphic features.

Intellectual disability and developmental delay affects 1-3% of the population and results from extraordinary heterogeneous environmental, chromosomal and monogenic causes. Detailed analysis of the Online Mendelian Inheritance in Man (OMIM) database and literature searches revealed more than a thousand entries for ID and DD, and more than 290 genes involved in clinical phenotypes or syndromes, metabolic or neurological disorders characterised by ID/DD.

The genetic changes of microdeletions/duplications are often not detectable by the current band resolution using routine or high resolution karyotyping (2-5 Mb) but require the application of molecular cytogenetic techniques such as Fluorescence In Situ Hybridisation (FISH), MLPA or array Comparative Genomic Hybridisation (aCGH).

Probemix content
The SALSA MLPA Probemix P064-C2 Microdeletion Syndromes-1B contains 52 MLPA probes with amplification products between 130 and 483 nucleotides (nt). The probes detect sequences involved in a distinct subset of microdeletion and microduplication disorders (described above). Complete probe sequences are available online (www.mrcholland.com).

This probemix contains nine quality control fragments generating amplification products between 64 and 105 nt: four DNA Quantity fragments (Q-fragments), two DNA Denaturation fragments (D-fragments), one Benchmark fragment, and one chromosome X and one chromosome Y-specific fragment. More information on how to interpret observations on these control fragments can be found in the MLPA General Protocol and online at www.mrcholland.com.