Preimplantation Genetic Diagnosis (PGD)

Prior to the use of PGD, genetic disease diagnosis was limited to testing a fetus through the common methods of amniocentesis and chorionic villus sampling (CVS). However, PGD provides a couple with more conclusive information about the health of the fetus. Knowing the genetic health of the fetus provides a couple with the tools to make informed decisions about the path a pregnancy should take.

Embryo Biopsy

In order to screen a human embryo before it is transferred to the mother’s uterus for gestation, one or two cells from a multi-celled embryo are removed for analysis. In more routine genetic analysis, there are usually hundreds of cells available for processing. However, with only one or two cells available, each must contain a nucleus with chromosomes present to determine the genetic status of the rest of the embryo.

Embryos are typically biopsied at day three of development. At this point the embryo is composed of between four and 12 cells that are still distinct from each other. By day three or day four at the latest, the embryo begins to compact, a process whereby the individual cells lose their clear outline and seem to fuse together with the other cells to form what is called the morula-stage embryo. On the third day single cells can be individually removed without disrupting the adjacent cells in the embryo.

Families affected by essentially any inherited disease can reduce the risk their offspring will suffer that genetic disorder, as well as families in search of a bone marrow donor may be able to use PGD to bring a child into the world that can provide matching stem cells.

Historical & Practical Factors

Pre-selecting embryos began as a way for families with histories of sex-linked genetic diseases who wanted to avoid conceiving children with the disease. In Australia and the U.K., PGD is highly regulated by governments; its use is allowed only in cases where the unborn child is at risk of having a genetic disease. PGD is also sometimes used for gender selection.

With a price tag of $15,000 per procedure, PGD is usually reserved strictly for patients known to be at risk of passing on genetic diseases. Insurance usually does not cover PGD.

Below follows a partial list of diseases that can be detected by REACH’s PGD partners, Genesis Genetics Institute:

A
Aarskog (X-FGD1)
Achondroplasia (FGFR3)
Actin-Nemalin Myopathy (ACTA1)
Adenomatous Polyposis Coli (FAP-APC)
Adrenoleukodystrophy (ABCD1)
Agammaglobulinemia-Bruton (BTK)
Alagille Syndrome (JAG1)
Aldolase A deficiency (ALDOA)
Alpha Thalassemia (HBA1)
Alpha Thalassemia/Mental Retard (ATRX)
Alpha-1-Antitrypsin Deficiency (AAT)
Alport Syndrome (COL4A5)
ALS: Amyotrophic Lateral Sclerosis 1, (SOD1)
Alzheimer Disease 3 (PSEN1)
Amegakaryocytic Thrombocytopenia, Congenital (CAMT)
Amyloidosis I-Transthyretin (TTR)
Angioedema, Hereditary (C1NH)
Ankylosing spondylitis (Susceptibility to, HLA-B27)
Antithrombin Deficiency (SERPINC1)
Apert Syndrome (FGFR2)
Ataxia Telangiectasia (ATM)
B
Basal Cell (Gorlin) Synd (PTCH)
Beta Thalassemia (HBB)
Bloom Syndrome (BLM)
Brachydactyly-Type C (GDF5)
Breast Cancer (BRCA1 & 2)
C
CACH-Ataxia (EIF2B4)
CADASIL (Notch3)
Canavan Disease (ASPA)
Cardiomyopathy, Barth Type Dilated (TAZ)
Cardiomyopathy, Dilated Hypertrophic (MYH7)
Dilated Hypertrophic Cardiomyopathy MYH7
Carnitine-AcylCarn Translocase (SLC25A20)
Ceroid-Lipofuscinoses-Batten Disease (PPT1)
Ceroid-Lipofuscinoses-Finish Type (CLN5)
Ceroid-Lipofuscinoses-Juvenile Type (CLN3)
Charcot Marie Tooth 1A (PMP22)
Charcot Marie Tooth Neuropathy - 2E, (NF-L, NEFL)
Charcot-Marie-Tooth neuropathy 1B (MPZ)
Cherubism (SH3BP2)
Choroideremia (CHM)
Chronic Granulomatous Disease (CYBB)
Citrullinemia (ASS)
Cleidocranial Dysplasia (RUNX2)
Cockayne syndrome type B (CSB; ERCC6)
Colon Cancer (HNPCC; MSH2)
Congenital Adrenal Hyperplasia (CYP21A2 )
Congenital Disorder Glycosylation, 1a - CDG-1a (PMM2)
Congenital Disorder Glycosylation, 1c - CDG-1c (ALG6)
Congenital Disorder Glycosylation, 1e - CDG-1e (DPM1)
Congenital Disorder Glycosylation, 1g - CDG-1g (ALG12)
Congenital Erythropoietic Porphyria (UROS)
Cosman-Cyclic Neutropenia (ELA2)
Crigler Najjar (UGT1A1)
Crouzon Syndrome (FGFR2)
Cystic Fibrosis (CFTR)
Cystinosis (CTNS)
D
Darier Disease (ATP2A2)
Deafness, Recessive - (GJB2 Connexin 26)
Deafness, Recessive - (GJB6 Connexin 30)
Deafness, Recessive (DFBN1)
Denys-Drash Wilms Tumor (WT1)
Desmin Storage Myopathy (DES)
Diamond Blackfan (DBA-RPS19)
Diamond Blackfan (DBA2) Not RPS19
Duchenne muscular dystrophy (DMD)
Dystonia (TOR1A)
Dystrophia Myotonica-1 (DMPK) CTGrpt
Dystrophia Myotonica-2 (DM2; PROMM) CCTGrpt
E
Ectodermal Dysplasia I EDA1
Ehlers-Danlos COL3A1
Emery-Dreifuss X-Linked Muscular Dystrophy
Emery-Dryfuss AutoDom Muscular Dystrophy (LMNA)
Epidermolysis Bullosa (KRT5)
Epidermolysis Bullosa Simplex KRT14
Epidermolysis Bullosa/Pyloric Atresia - ITGB4
Epidermolysis Dystrophic Bullosa-COL7A1
Epidermolytic Hyperkeratosis (KRT10)
F
Fabry (GLA)
Facioscapulohumeral Dystrophy (FSHD)
Factor 13 Deficiency (F13A1)
Familial Dysautonomia (IKBKAP)
Familial Exudative Vitreoretinopathy FZD4
Fanconi Anemia A (FANCA)
Fanconi Anemia C (FANCC)
Fanconi Anemia F (FANC F)
Fanconi Anemia J (FANCJ, BRIP1)
Fanconia Anemia G (FANCG)
Fragile X (FMR1)
Friedreich Ataxia I (FRDA)
G
Galactosemia (GALT)
Gastric Cancer, Cadherin-E-1 (CDH1)
Gaucher Disease (GBA)
Genotyping-Molecular Signature-Fingerprinting
Glutaric Acidemia 2A (ETFA)
Glycine Encephalopathy GLDC 80% (NKH)
Glycogen Storage Disease I, Von Girke - GSD1a (G6PC)
Glycogen Storage Disease 2, Pompe - GSD2 (GAA)
GM1 Gangliosidosis, Morquio (GLB1)
H
Hallervorden-Spatz-Pantothenate (PANK2)
Hemophilia A (Factor 8)
Hemophilia B (Factor 9)
Hereditary Hemmorrhagic Telangietasia Type 1 (HHT1)
Histiocytosis, Hemophagocytic Lympho- (HLH; PRF1)
HLA DRBeta1 Class II MHC (HLA DRB1*)
HLA-Histocompatability, Transplantation Matching (HLA)
Hunter syndrome (IDS)
Huntington Disease (HD)
Hurler Syndrome (MPSI-IDUA)
Hydrocephalus:X-Linked L1CAM
Hyper IgM (CD40-ligand; TNFSF5)
Hypokalemic periodic paralysis (SCN4A-HYPP)
Hypophosphatasia (ALPL)
Hypophosphatemic VitD Rickets
I
Icthyosis, X-Steroid Sulf Def
Icthyosis.Congenital, Harlequin (ABCA12)
Incontinentia Pigmenti (NEMO)
J
K
KELL Antigen (KEL)
Kennedy-Spinal bulbar (AR)
Krabbe (GALC)
L
Leber Retinal Congenital Amaurosis-I (GUCY2D)
Leber Retinal Congenital Amaurosis-X (CEP290)
Lesch-Nyhan (HPRT1)
Leukemia, Acute Lymphocytic, Transplantation (ALL)
Leukemia, Acute Myelogenous, Transplantation (AML)
Leukemia, Chronic Myelogenous, Transplantation (CML)
Leukocyte Adhesion Deficiency (ITGB2)
Li-Fraumeni Syndrome (TP53)
Long-Chain-AcylCoA Dehydrogenase (LCHAD:HADHA)
Lymphedema-Hereditary (FOXC2)
Lymphoproliferative Disorder, X-linked (SH2D1A)
M
Machado-Joseph Spinocerebellar Ataxia-3 (SCA3)
Macular Dystr-Best Vitelliform (VMD2)
Maple Syurp Urine Dz E1-Beta (BCKDHB)
Marfan Syndrome (FBN1)
Meckel-Gruber Syndrome-3 (MKS3)
Menkes (ATP7A)
Merosin-deficient congenital muscular dystrophy type 1A (MDC1A)
Metachromatic Leukodystrophy (ARSA)
Methylcobalamin G Deficiency (MTR)
Methylmalonic Acidemia (MUT)
Mitochondrial Myopathy-Complex I (NDUFS4)
Mucolipidosis 2, I Cell (GNPTAB)
Multiple Endocrine Neoplasia 1 (MEN1)
Multiple Endocrine Neoplasia 2 MEN2 (RET)
Multiple Extostoses (EXT1)
Multiple Extostoses (EXT2)
Myasthenia Gravis (CHRNE)
Myotubular Myopathy X-Linked (MTM)
N
NEMO immunodeficiency (IKBKG)
Nephrosis - Finnish (NPHS1)
Neurofibromatosis 1 (NF1)
Neurofibromatosis 2 (NF2)
Niemann Pick - Type A (SMPD1)
Niemann Pick - Type C (NPC1)
NonKetotic Hyperglycinemia (GLDC)
Noonan (PTPN11)
Norrie (NDP)
O
Occulocutaneous Albinism II- (OCA2)
Occulocutaneous Albinism I, OCA1 (TYR)
Ocular Albinism-X Linked (GPR143)
Oculodentodigital Dysplasia (GJA1)
Optic Atrophy 1 (OPA1)
Ornithine transcarbamylase deficiency (OTC)
Osteogenesis Imper II/IV & Chondrodysplasias(COL1A2)
Osteogenesis Imperfecta I (COL1A1)
Osteopetrosis (CLCN7)
Osteopetrosis (TCIRG1;APT6)
P
Pachyonychia Congenita (KRT6A)
Pachyonychia Congenita (KRT16A)
Pancreatitis, Chronic Calcific (PRSS1)
Paraganglioma-Nonchromaffin (SDHB)
Pelizaeus-Merzbacher, X-linked (PLP1)
Periventricular Heteropia (FLNA)
Persistent Hyperinsulinemic Hypoglycemia of Infancy (ABCC8)
Pfeiffer Syndrome (FGFR2)
Phenylketonuria PKU (PAH)
Pheochromocytoma (SDHB)
Polycystic Kidney Disease (PKD1)
Polycystic Kidney Disease (PKD2)
Polycystic Kidney Disease, Recessive (PKHD1)
Pompe, Glycogen Storage Disease 2, GSD2 (GAA)
Propionic Acidemia (PCCA)
Pseudohypoparathyroidism 1a (GNAS1)
Q
R
Retinitis Pigmentosa (RHO)
Retinitis Pigmentosa adRP10 (IMPDH1)
Retinitis Pigmentosa X-linked (RPGR)
Retinoblastoma 1 (RB1)
Retinoschisis, (RS1)
Rhesus blood group D (RHD)
Rhizomelic Chondrodysplasia Punctata (RCDP1)
S
Sacral Agenesis (HLXB9)
Sanfilippo A (MPSIIIA)
Sanfillipo B (MPSIIIB) (NAGLU)
Sathre-Chotzen Craniosynostosis (TWIST)
SCIDX1 (IL2RG)
Severe Comb Immunodef (SCID)
Shwachman-Diamond Syndrome (SBDS)
Sickle Cell (HBB)
Smith-Lemli-Opitz (SLOS)
Sorsby Fundus Dystrophy (TIMP3)
Spinal muscular atrophy SMA (SMN1)
Spinocerebellar Ataxia-1, SCA1 (ATNX1)
Spinocerebellar ataxia-2, SCA2 (ATXN2)
Spinocerebellar Ataxia-3, Machado-Joseph (SCA3)
Spinocerebellar Ataxia-7 (ATXN7)
Spondyloepiphyseal dysplasia, congenital (SEDc)
Steroid Sulfatase Deficiency (STS)
Stomach-Ovarian-Endometrial Cancer (CDH1)
Supravalvular Aortic Stenosis (ELN)
Surfactant-Pulmonary B (SFTPB)
T
Tay-Sachs (HEXA)
Torsion dystonia (DYT1)
Treacher Collins (TCOF1)
Transplantation-BoneMarrow-StemCell (HLA locus)
Tuberous Sclerosis 1 (TSC1)
Tuberous Sclerosis 2 (TSC2)
U
V
VanderWoude -Popliteal Pterygium (IRF6)
Von Hippel-Lindau Disease (VHL)
W
Waardenburg Syndrome Type II (MITF)
Waardenburg Syndrome-I/III (PAX3)
West Syndrome (ARX)
Wilms Tumor (WT1)
Wiskott-Aldrich Syndrome (WAS)
Wolman Lipase A (LIPA)
X
Y
Z
Zellweger Peroxisome Disease (PEX1)