TY  - JOUR
A1  - Hofrichter, Michaela A. H.
A1  - Mojarad, Majid
A1  - Doll, Julia
A1  - Grimm, Clemens
A1  - Eslahi, Atiye
A1  - Hosseini, Neda Sadat
A1  - Rajati, Mohsen
A1  - Müller, Tobias
A1  - Dittrich, Marcus
A1  - Maroofian, Reza
A1  - Haaf, Thomas
A1  - Vona, Barbara
T1  - The conserved p.Arg108 residue in S1PR2 (DFNB68) is fundamental for proper hearing: evidence from a consanguineous Iranian family
JF  - BMC Medical Genetics
N2  - Background:
Genetic heterogeneity and consanguineous marriages make recessive inherited hearing loss in Iran the second most common genetic disorder. Only two reported pathogenic variants (c.323G>C, p.Arg108Pro and c.419A>G, p.Tyr140Cys) in the S1PR2 gene have previously been linked to autosomal recessive hearing loss (DFNB68) in two Pakistani families. We describe a segregating novel homozygous c.323G>A, p.Arg108Gln pathogenic variant in S1PR2 that was identified in four affected individuals from a consanguineous five generation Iranian family.

Methods:
Whole exome sequencing and bioinformatics analysis of 116 hearing loss-associated genes was performed in an affected individual from a five generation Iranian family. Segregation analysis and 3D protein modeling of the p.Arg108 exchange was performed.

Results:
The two Pakistani families previously identified with S1PR2 pathogenic variants presented profound hearing loss that is also observed in the affected Iranian individuals described in the current study. Interestingly, we confirmed mixed hearing loss in one affected individual. 3D protein modeling suggests that the p.Arg108 position plays a key role in ligand receptor interaction, which is disturbed by the p.Arg108Gln change.

Conclusion:
In summary, we report the third overall mutation in S1PR2 and the first report outside the Pakistani population. Furthermore, we describe a novel variant that causes an amino acid exchange (p.Arg108Gln) in the same amino acid residue as one of the previously reported Pakistani families (p.Arg108Pro). This finding emphasizes the importance of the p.Arg108 amino acid in normal hearing and confirms and consolidates the role of S1PR2 in autosomal recessive hearing loss.
KW  - 3D modeling
KW  - autosomal recessive non-synstromic hearing loss
KW  - DFNB68
KW  - mixed hearing loss
KW  - whole exome sequencing
KW  - S1PR2
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-175755
VL  - 19
IS  - 81
ER  - 
TY  - JOUR
A1  - Vona, Barbara
A1  - Maroofian, Reza
A1  - Bellacchio, Emanuele
A1  - Najafi, Maryam
A1  - Thompson, Kyle
A1  - Alahmad, Ahmad
A1  - He, Langping
A1  - Ahangari, Najmeh
A1  - Rad, Abolfazl
A1  - Shahrokhzadeh, Sima
A1  - Bahena, Paulina
A1  - Mittag, Falk
A1  - Traub, Frank
A1  - Movaffagh, Jebrail
A1  - Amiri, Nafise
A1  - Doosti, Mohammad
A1  - Boostani, Reza
A1  - Shirzadeh, Ebrahim
A1  - Haaf, Thomas
A1  - Diodato, Daria
A1  - Schmidts, Miriam
A1  - Taylor, Robert W.
A1  - Karimiani, Ehsan Ghayoor
T1  - Expanding the clinical phenotype of IARS2-related mitochondrial disease
JF  - BMC Medical Genetics
N2  - Background:
IARS2 encodes a mitochondrial isoleucyl-tRNA synthetase, a highly conserved nuclear-encoded enzyme required for the charging of tRNAs with their cognate amino acid for translation. Recently, pathogenic IARS2 variants have been identified in a number of patients presenting broad clinical phenotypes with autosomal recessive inheritance. These phenotypes range from Leigh and West syndrome to a new syndrome abbreviated CAGSSS that is characterised by cataracts, growth hormone deficiency, sensory neuropathy, sensorineural hearing loss, and skeletal dysplasia, as well as cataract with no additional anomalies.

Methods:
Genomic DNA from Iranian probands from two families with consanguineous parental background and overlapping CAGSSS features were subjected to exome sequencing and bioinformatics analysis.

Results:
Exome sequencing and data analysis revealed a novel homozygous missense variant (c.2625C > T, p.Pro909Ser, NM_018060.3) within a 14.3 Mb run of homozygosity in proband 1 and a novel homozygous missense variant (c.2282A > G, p.His761Arg) residing in an ~ 8 Mb region of homozygosity in a proband of the second family. Patient-derived fibroblasts from proband 1 showed normal respiratory chain enzyme activity, as well as unchanged oxidative phosphorylation protein subunits and IARS2 levels. Homology modelling of the known and novel amino acid residue substitutions in IARS2 provided insight into the possible consequence of these variants on function and structure of the protein.

Conclusions:
This study further expands the phenotypic spectrum of IARS2 pathogenic variants to include two patients (patients 2 and 3) with cataract and skeletal dysplasia and no other features of CAGSSS to the possible presentation of the defects in IARS2. Additionally, this study suggests that adult patients with CAGSSS may manifest central adrenal insufficiency and type II esophageal achalasia and proposes that a variable sensorineural hearing loss onset, proportionate short stature, polyneuropathy, and mild dysmorphic features are possible, as seen in patient 1. Our findings support that even though biallelic IARS2 pathogenic variants can result in a distinctive, clinically recognisable phenotype in humans, it can also show a wide range of clinical presentation from severe pediatric neurological disorders of Leigh and West syndrome to both non-syndromic cataract and cataract accompanied by skeletal dysplasia.
KW  - adrenal insufficiency
KW  - CAGSSS
KW  - cataracts
KW  - growth hormone deficiency
KW  - IARS2
KW  - sensory neuropathy
KW  - sensorineural hearing loss
KW  - type II esophageal achalasia
KW  - skeletal dysplasia
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-176620
VL  - 19
IS  - 196
ER  - 
TY  - JOUR
A1  - Dubail, Johanne
A1  - Huber, Céline
A1  - Chantepie, Sandrine
A1  - Sonntag, Stephan
A1  - Tüysüz, Beyhan
A1  - Mihci, Ercan
A1  - Gordon, Christopher T.
A1  - Steichen-Gersdorf, Elisabeth
A1  - Amiel, Jeanne
A1  - Nur, Banu
A1  - Stolte-Dijkstra, Irene
A1  - van Eerde, Albertien M.
A1  - van Gassen, Koen L.
A1  - Breugem, Corstiaan C.
A1  - Stegmann, Alexander
A1  - Lekszas, Caroline
A1  - Maroofian, Reza
A1  - Karimiani, Ehsan Ghayoor
A1  - Bruneel, Arnaud
A1  - Seta, Nathalie
A1  - Munnich, Arnold
A1  - Papy-Garcia, Dulce
A1  - De La Dure-Molla, Muriel
A1  - Cormier-Daire, Valérie
T1  - SLC10A7 mutations cause a skeletal dysplasia with amelogenesis imperfecta mediated by GAG biosynthesis defects
JF  - Nature Communications
N2  - Skeletal dysplasia with multiple dislocations are severe disorders characterized by dislocations of large joints and short stature. The majority of them have been linked to pathogenic variants in genes encoding glycosyltransferases, sulfotransferases or epimerases required for glycosaminoglycan synthesis. Using exome sequencing, we identify homozygous mutations in SLC10A7 in six individuals with skeletal dysplasia with multiple dislocations and amelogenesis imperfecta. SLC10A7 encodes a 10-transmembrane-domain transporter located at the plasma membrane. Functional studies in vitro demonstrate that SLC10A7 mutations reduce SLC10A7 protein expression. We generate a Slc10a7−/− mouse model, which displays shortened long bones, growth plate disorganization and tooth enamel anomalies, recapitulating the human phenotype. Furthermore, we identify decreased heparan sulfate levels in Slc10a7−/− mouse cartilage and patient fibroblasts. Finally, we find an abnormal N-glycoprotein electrophoretic profile in patient blood samples. Together, our findings support the involvement of SLC10A7 in glycosaminoglycan synthesis and specifically in skeletal development.
KW  - bone development
KW  - disease genetics
KW  - medical genetics
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-226377
VL  - 9
ER  -