Genomic and genic deletions of the FOX gene cluster on 16q24.1 and inactivating mutations of FOXF1 cause alveolar capillary dysplasia and other malformations.
Alveolar capillary dysplasia with misalignment of pulmonary veins (ACD/MPV) is a rare, neonatally lethal developmental disorder of the lung with defining histologic abnormalities typically associated with multiple congenital anomalies (MCA). Using array CGH analysis, we have identified six overlapping microdeletions encompassing the FOX transcription factor gene cluster in chromosome 16q24.1q24.2 in patients with ACD/MPV and MCA. Subsequently, we have identified four different heterozygous mutations (frameshift, nonsense, and no-stop) in the candidate FOXF1 gene in unrelated patients with sporadic ACD/MPV and MCA. Custom-designed, high-resolution microarray analysis of additional ACD/MPV samples revealed one microdeletion harboring FOXF1 and two distinct microdeletions upstream of FOXF1, implicating a position effect. DNA sequence analysis revealed that in six of nine deletions, both breakpoints occurred in the portions of Alu elements showing eight to 43 base pairs of perfect microhomology, suggesting replication error Microhomology-Mediated Break-Induced Replication (MMBIR)/Fork Stalling and Template Switching (FoSTeS) as a mechanism of their formation. In contrast to the association of point mutations in FOXF1 with bowel malrotation, microdeletions of FOXF1 were associated with hypoplastic left heart syndrome and gastrointestinal atresias, probably due to haploinsufficiency for the neighboring FOXC2 and FOXL1 genes. These differences reveal the phenotypic consequences of gene alterations in cis.
Stankiewicz
Paweł
P
Dept of Molecular & Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA. pawels@bcm.edu
Sen
Partha
P
Bhatt
Samarth S
SS
Storer
Mekayla
M
Xia
Zhilian
Z
Bejjani
Bassem A
BA
Ou
Zhishuo
Z
Wiszniewska
Joanna
J
Driscoll
Daniel J
DJ
Maisenbacher
Melissa K
MK
Bolivar
Juan
J
Bauer
Mislen
M
Zackai
Elaine H
EH
McDonald-McGinn
Donna
D
Nowaczyk
Małgorzata M J
MM
Murray
Mitzi
M
Hustead
Virginia
V
Mascotti
Kristin
K
Schultz
Regina
R
Hallam
Lavinia
L
McRae
Duncan
D
Nicholson
Andrew G
AG
Newbury
Robert
R
Durham-O'Donnell
Jane
J
Knight
Gail
G
Kini
Usha
U
Shaikh
Tamim H
TH
Martin
Vicki
V
Tyreman
Matthew
M
Simonic
Ingrid
I
Willatt
Lionel
L
Paterson
Joan
J
Mehta
Sarju
S
Rajan
Diana
D
Fitzgerald
Tomas
T
Gribble
Susan
S
Prigmore
Elena
E
Patel
Ankita
A
Shaffer
Lisa G
LG
Carter
Nigel P
NP
Cheung
Sau Wai
SW
Langston
Claire
C
Shaw-Smith
Charles
C
D000015:Abnormalities, Multiple / Q000235:genetics; D001997:Bronchopulmonary Dysplasia / Q000235:genetics*; D002196:Capillaries / Q000002:abnormalities; D002675:Child, Preschool; D002874:Chromosome Mapping; D002885:Chromosomes, Human, Pair 16 / Q000235:genetics*; D004317:Doxorubicin / Q000031:analogs & derivatives; D005260:Female; D051858:Forkhead Transcription Factors / Q000235:genetics*; D017353:Gene Deletion; D020868:Gene Silencing; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D009154:Mutation / Q000235:genetics*; D011650:Pulmonary Alveoli / Q000098:blood supply / Q000473:pathology*; D011667:Pulmonary Veins / Q000002:abnormalities
C098521:FOXF1 protein, human; C491001:FOXL1 protein, human; D051858:Forkhead Transcription Factors; C082078:mesenchyme fork head 1 protein; C049732:7-O-(2,6-dideoxy-2-fluorotalopyranose)adriamycinone; D004317:Doxorubicin