SUFWprenatalArray

SUFWprenatalArray

Prenatal testing for genetic abnormalities using microarray CGH with qfPCR.

Most women enjoy a healthy pregnancy however some babies are born with physical and developmental problems and about one sixth of these are due to changes in the chromosomes.

What are chromosomes abnormalities?

Chromosomes are structures in our body’s cells made up of DNA that contains information which tells our body how to grow and function. There are 23 pairs of chromosomes, one half of each pair inherited from each parent and are numbered from 1 to 22. The 23rd pair is the sex chromosomes determining the sex of the baby. A chromosomal abnormality occurs when there is too much or too little DNA and this can cause physical and developmental problems.

Until recently, standard chromosome testing using a microscope to analyse cells from a prenatal sample obtained from either CVS or amniocentesis was the only one used. This standard test is not able to detect very small (submicroscopic) imbalances in the chromosomes and the result takes 10-14 days. QfPCR (quantitative fluorescent polymerase chain reaction) or fast DNA has been added to provide a preliminary result for 5 chromosomes in 1-2 working days. This will identify about 90% of the common chromosome abnormalities where there is a loss or gain in chromosome number (aneuploidy).

What is microarray CGH?

A new, fast, reliable, high resolution test called microarray comparative genomic hybridization (microarray CGH) is now available. This new molecular genetic technology allows prenatal testing of over 250 genetic disorders (see below for detailed list) that are not detected on standard chromosome testing, making it a superior test. These genetic disorders may occur in women of any age causing intellectual disability or serious birth defects. At SUFW a custom made targeted microarray is used to identify the most severe of these disorders and to minimize the limitations of this testing.

What does it test for?

Microarray CGH is able to detect aneuploidy and the very small chromosome imbalances not detected on standard chromosome testing. These imbalances are called microdeletions and microduplications. It is always combined with qfPCR.

How is the test done?

The DNA from a CVS or amniotic fluid sample is compared with a control (normal) DNA sample. Short coloured segments of DNA from the prenatal sample are mixed with the control sample of a different colour. The samples bind together enabling a comparison to be made and imbalances of DNA detected in the prenatal sample. Known imbalances predict an abnormal outcome.

What are there limitations of this testing?

There are some genetic disorders that cannot be identified using this test but these are rare and if there is a concern other genetic or chromosome testing can be performed.

In a small number of cases (5-10%), the imbalances identified are benign, having no effect on your baby and are not associated with a genetic disorder. Testing both parents may reveal these imbalances to be inherited. Imbalances are also known as DNA copy number variations or CNV’s. In less than 1% of CNV’s the imbalances are of uncertain significance and additional testing and genetic counselling is provided for such unexpected results.

How long do the results take?

Microarray CGH results take 7 days, with the qfPCR preliminary result known in 1-2 working days.

When will microarray be offered?

This test will replace the standard chromosome test and be offered following a high risk result on combined first trimester screening or the discovery of a structural fetal abnormality. As it is faster and more comprehensive than the standard test, many women may elect to undertake this testing as the procedure-related risk with CVS or amniocentesis is known to be low at SUFW where the doctors have an excellent reputation for safe prenatal testing (miscarriage risk less than 1/300).

Syndrome List

10q22.3

10q22

11q14 Microdeletion

12q14.1

12q14.3 deletion

13q21.32 del Protocadherin 9

14q11.2 deletion

14q11.2 Microdeletion

14q12 deletion

14q22 Microdeletion

14q22 Microdeletion, Microphthalmia, syndromic 5

14q22 Microdeletion, Orofacial cleft 11

14q22

15q13.3 Microdeletion

15q15.3 infertility and deafness

16p13.1 Microdeletion predisposing to autism and/or mental retardation

16p13.2 deletion

16p13.3 Microdeletion/sever rubinstein

17q12 Microdeletion

17q21.3 Microdeletion

17q21.31

1p36 Microdeletion

1q41

22q11.2 distal microdeletion

22q11.21 Microduplication

22q13.3 Microdeletion

2p15

2q32.2

2q37

3q29 Microdeletion

6p25 Microdeletion (including FOXC1)

6q24.3 Microdeletion

8p23.1 Microdeletion

8q24.3

9q22.32

9q34 Microdeletion

Aarskog

Adrenal hypoplasia congenita

Adrenoleukodystrophy; (ALD)

Alagille Syndrome

Albright Hereditary osteodystrophy

Albright hereditary osteodystrophy

Allan

Alpha thalassemia mental retardation

Alport syndrome (X)

Androgen insensitivity syndrome

Angelman / Prader Willi

Aniridia

Syndrome List

Aniridia II

Atrial septal defect (ASD) with atrioventricular conduction defects

Basal cell nevus/Gorlin

Beckwith

Bilateral frontoparietal polymicrogyria

Borjeson

Boston

Brachydactyl type C

Branchio

Brunner Syndrome

Campomelic dysplasia

Cat

Cerebral amyloid angiopathy

Charcot

CHARGE syndrome

Choroideremia

Chromosome 18q Deletion Syndrome

Chromosome 6pter

Chromosome 9p Deletion Syndrome

Chronic granulomatous disease

Cleidocranial dysplasia (CCD)

Coffin

Congenital diaphragmatic hernia

Congenital diaphragmatic hernia 2 (CDH2)

Congenitial adrenal hyperplasia (CAH)

Cornelia de Lange

Craniostenosis (Craniosynostosis )

Creatine deficiency syndrome / X

Creatine deficiency syndrome, XLMR

Cri du chat

Currarino Syndrome

Cystinosis

Cystinuria with mitochondrial disease

Dandy Walker

Deafness

Diamond Blackfan anemia

diGeorge

diGeorge 1

diGeorge 2

DiGeorge/Velocardiofacial (VCF)

Down Syndrome Critical Region

Dyggve

Ectodermal dysplasia

Ehlers

Fabry disease

Fanconi Anemia

Feingold

FMR1 Microdeletion

Syndrome List

Focal dermal hypoplasia/Goltz

Fragile X (FMR1 and FMR2 deletion)

Fryns 1q41

Glycerol Kinase deficiency

GREIG CEPHALOPOLYSYN DACTYLY SYNDROME

Hemophila

Hereditary Hemorrhagic Telangiectasia Syndrome

Heterotopia, Periventricular, X

Hirschsprung Disease Plus

Holopresencaphly 2

Holopresencaphly 4

Holopresencaphyl 5

HOLOPROSENCEPH ALY 7

Holoprosencephaly 1

Holoprosencephaly 3

Holoprosencephaly 9

Holoprosencephaly and preaxial polydactly

Holt

HSAS, MASA, CRASH syndromes

Hunter syndrome, Mucopolysaccharidosi s type II

Hypo phosphatemic rickets

Hypomyelination, Global Cerebral

Hypoparathyroidis, sensorineural deafness, renal disease (HDR)

Incontinentia Pigmenti

Infantile hyperinulinism, enteropathy and deafness (Ushers disease)

Joubert 4

Joubert 5

Kabuki Syndrome

Kallman 1

Kallmann

Langer

Leri

Lesch

Leukodystrophy

Lissencephaly with cerebellar hypoplasia

Loeys

Lowe

Marfan Syndrome

UPD14 (Uniparental phenomenon)

Meningioma / NF2

Menkes disease

Mental retardation associated with Alpha thalaessamia

Mental retardation X linked Xq27.1 dup and del

Mental Retardation, Autosomal Recessive 6; MRT6

Mental Retardation, X

Mental retardation, X

Mental Retardation, X

Metachromatic Leukodystrophy

Microphtthalmia

Syndrome List

Miller

Mohr

Monosomy 1p31 p22

Mowat

Muscular dystrophy

Myotubular Myopathy

Nail

Nephronophthisis 1

Neurofibromatosis 1

NFIA Haploinsufficiency

Noonan 1

Noonan 4

Noonan syndrome 5 (NS5)

Norrie disease

Oculocutaneous albinism 2

Okihiro

Oligodontia

Opitz

Opitz / FP syndrome

Ornithine transcarbamylase deficiency

Orofaciodigital 1

Osteogenesis imperfecta

Parietal foramina

Pelizaeus

Pitt Hopkins

Polycystic kidney disease

Polydactyly, Preaxial II

Potocki

Pseudovaginal perineoscrotal hypospadias

Pyruvate dehydrogenase deficiency

Retinoblastoma

Retts

Rieger

Rolandic epilepsy, mental retardation, and speech dyspraxia, X

Rubinstein Taybi Syndrome

Saethre

Schizencephaly

SCN1A

Severe myoclonic epilepsy of infancy (SMEI)

sex reversal, autosomal dominant 2 (SRA2)

Silver

Simpson

Smith

SOTOS

Syndrome List

Split/hand foot malformation

SRY deletion

Steroid sulfatase definiciency

Sticker 1

Stickler syndrome

Synpolydactyly

Thrombocytopenia absent radius syndrome

Timothy syndrome

Townes Brocks

Trischororhinophlange al, Langer

Tuberous sclerosis

Tuberous schlerosis, polycystic kidney disease

Ulnar

Van der Woude

Visceral heterotaxy

Von Hippel Lindau

Waardenburg syndrome I

Waardenburg syndrome IIA

Waardenburg syndrome type 2/2E

WAGR Syndrome probes

Williams

Wolf

Xp11.22

Xp11.3 microdeletion

XX male

XY Gonadal dysgenesis

XY sex reversal

End