High-throughput sequencing of a 4.1 Mb linkage interval reveals FLVCR2 deletions and mutations in lethal cerebral vasculopathy.
Rare lethal disease gene identification remains a challenging issue, but it is amenable to new techniques in high-throughput sequencing (HTS). Cerebral proliferative glomeruloid vasculopathy (PGV), or Fowler syndrome, is a severe autosomal recessive disorder of brain angiogenesis, resulting in abnormally thickened and aberrant perforating vessels leading to hydranencephaly. In three multiplex consanguineous families, genome-wide SNP analysis identified a locus of 14 Mb on chromosome 14. In addition, 280 consecutive SNPs were identical in two Turkish families unknown to be related, suggesting a founder mutation reducing the interval to 4.1 Mb. To identify the causative gene, we then specifically enriched for this region with sequence capture and performed HTS in a proband of seven families. Due to technical constraints related to the disease, the average coverage was only 7×. Nonetheless, iterative bioinformatic analyses of the sequence data identified mutations and a large deletion in the FLVCR2 gene, encoding a 12 transmembrane domain-containing putative transporter. A striking absence of alpha-smooth muscle actin immunostaining in abnormal vessels in fetal PGV brains, suggests a deficit in pericytes, cells essential for capillary stabilization and remodeling during brain angiogenesis. This is the first lethal disease-causing gene to be identified by comprehensive HTS of an entire linkage interval.
Thomas
Sophie
S
INSERM U-781, Hôpital Necker-Enfants Malades, Paris, France.
Encha-Razavi
Ferechté
F
Devisme
Louise
L
Etchevers
Heather
H
Bessieres-Grattagliano
Bettina
B
Goudefroye
Géraldine
G
Elkhartoufi
Nadia
N
Pateau
Emilie
E
Ichkou
Amale
A
Bonnière
Maryse
M
Marcorelle
Pascale
P
Parent
Philippe
P
Manouvrier
Sylvie
S
Holder
Muriel
M
Laquerrière
Annie
A
Loeuillet
Laurence
L
Roume
Joelle
J
Martinovic
Jelena
J
Mougou-Zerelli
Soumaya
S
Gonzales
Marie
M
Meyer
Vincent
V
Wessner
Marc
M
Feysot
Christine Bole
CB
Nitschke
Patrick
P
Leticee
Nadia
N
Munnich
Arnold
A
Lyonnet
Stanislas
S
Wookey
Peter
P
Gyapay
Gabor
G
Foliguet
Bernard
B
Vekemans
Michel
M
Attié-Bitach
Tania
T
D001921:Brain / Q000098:blood supply; D002883:Chromosomes, Human, Pair 14 / Q000235:genetics; D003241:Consanguinity; D005333:Fetus / Q000098:blood supply; D008040:Genetic Linkage; D057166:High-Throughput Screening Assays / Q000379:methods*; D006801:Humans; D006832:Hydranencephaly / Q000235:genetics*; D006849:Hydrocephalus / Q000235:genetics; D026901:Membrane Transport Proteins / Q000737:chemistry / Q000235:genetics*; D009154:Mutation; D009389:Neovascularization, Pathologic; D010375:Pedigree; D020641:Polymorphism, Single Nucleotide; D011991:Receptors, Virus / Q000737:chemistry / Q000235:genetics*; D017422:Sequence Analysis, DNA; D017384:Sequence Deletion; D014652:Vascular Diseases / Q000235:genetics*
C553450:FLVCR2 protein, human; D026901:Membrane Transport Proteins; D011991:Receptors, Virus