Bi-allelic Mutations in PKD1L1 Are Associated with Laterality Defects in Humans.
Disruption of the establishment of left-right (L-R) asymmetry leads to situs anomalies ranging from situs inversus totalis (SIT) to situs ambiguus (heterotaxy). The genetic causes of laterality defects in humans are highly heterogeneous. Via whole-exome sequencing (WES), we identified homozygous mutations in PKD1L1 from three affected individuals in two unrelated families. PKD1L1 encodes a polycystin-1-like protein and its loss of function is known to cause laterality defects in mouse and medaka fish models. Family 1 had one fetus and one deceased child with heterotaxy and complex congenital heart malformations. WES identified a homozygous splicing mutation, c.6473+2_6473+3delTG, which disrupts the invariant splice donor site in intron 42, in both affected individuals. In the second family, a homozygous c.5072G>C (p.Cys1691Ser) missense mutation was detected in an individual with SIT and congenital heart disease. The p.Cys1691Ser substitution affects a highly conserved cysteine residue and is predicted by molecular modeling to disrupt a disulfide bridge essential for the proper folding of the G protein-coupled receptor proteolytic site (GPS) motif. Damaging effects associated with substitutions of this conserved cysteine residue in the GPS motif have also been reported in other genes, namely GPR56, BAI3, and PKD1 in human and lat-1 in C. elegans, further supporting the likely pathogenicity of p.Cys1691Ser in PKD1L1. The identification of bi-allelic PKD1L1 mutations recapitulates previous findings regarding phenotypic consequences of loss of function of the orthologous genes in mice and medaka fish and further expands our understanding of genetic contributions to laterality defects in humans.
Baylor Genetics, Houston, TX 77030, USA.
Francesco
F
Vetrini
Division of Cardiology, Texas Children's Hospital, Houston, TX 77030, USA; Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA.
Lisa C A
LC
D'Alessandro
Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA.
Zeynep C
ZC
Akdemir
Baylor Genetics, Houston, TX 77030, USA; Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA.
Alicia
A
Braxton
Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA.
Mahshid S
MS
Azamian
Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA.
Mohammad K
MK
Eldomery
Albany Medical Center, Albany, NY 12208, USA.
Kathryn
K
Miller
Albany Medical Center, Albany, NY 12208, USA.
Chelsea
C
Kois
Albany Medical Center, Albany, NY 12208, USA.
Virginia
V
Sack
Albany Medical Center, Albany, NY 12208, USA.
Natasha
N
Shur
Albany Medical Center, Albany, NY 12208, USA.
Asha
A
Rijhsinghani
Baylor Genetics, Houston, TX 77030, USA.
Jignesh
J
Chandarana
Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX 77030, USA.
Yan
Y
Ding
Genetics Department, Kaiser Permanente Medical Group, San Jose, CA 95123, USA.
Judy
J
Holtzman
Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX 77030, USA.
Shalini N
SN
Jhangiani
Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX 77030, USA.
Donna M
DM
Muzny
Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX 77030, USA.
Richard A
RA
Gibbs
Baylor Genetics, Houston, TX 77030, USA; Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA.
Christine M
CM
Eng
Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA; Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA.
Neil A
NA
Hanchard
Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA.
Tamar
T
Harel
Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA.
Jill A
JA
Rosenfeld
Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA.
John W
JW
Belmont
Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA; Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX 77030, USA.
James R
JR
Lupski
Baylor Genetics, Houston, TX 77030, USA; Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA. Electronic address: yapingy@bcm.edu.
Yaping
Y
Yang
D000483:Alleles; D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000818:Animals; D017173:Caenorhabditis elegans / Q000235:genetics; D003545:Cysteine / Q000235:genetics; D059472:Exome / Q000235:genetics; D005260:Female; D005315:Fetal Diseases / Q000235:genetics; D007839:Functional Laterality / Q000235:genetics*; D006330:Heart Defects, Congenital / Q000235:genetics; D059446:Heterotaxy Syndrome; D006720:Homozygote; D006801:Humans; D007231:Infant, Newborn; D007438:Introns / Q000235:genetics; D008297:Male; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics*; D051379:Mice; D008875:Middle Aged; D008958:Models, Molecular; D009154:Mutation; D020125:Mutation, Missense; D009990:Oryzias / Q000235:genetics; D010375:Pedigree; D012326:RNA Splicing / Q000235:genetics; D012857:Situs Inversus / Q000235:genetics*
D008565:Membrane Proteins; C455507:PKD1L1 protein, human; D003545:Cysteine