We characterized the X-chromosomal abnormality encompassing HCCS or an intragenic mutation in this gene in six new female patients with an MLS phenotype by cytogenetic analysis, fluorescence in situ hybridization, sequencing, and quantitative real-time PCR.
Microphthalmia with linear skin defects syndrome (MLS or MIDAS, OMIM #309801) is a rare X-linked male-lethal disorder characterized by microphthalmia or other ocular anomalies and skin lesions limited to the face and neck.
Mutations in HCCS on the C-terminal side of the CP motifs, known to cause disease states in humans (microphthalmia with linear skin defects) abolished or drastically attenuated holocytochrome c production.
We performed DNA sequencing of PORCN in 13 female patients with the clinical diagnosis of FDH as well as four female patients with MLS syndrome and no mutation in HCCS.
To analyze if mutations in HCCS, encoding the mitochondrial holocytochrome c-type synthase, are associated with phenotypes other than the microphthalmia with linear skin defects (MLS) syndrome, including severe eye malformations such as microphthalmia and/or anophthalmia.
We did obtain a single heterozygous deleted female that does not express human HCCS, which is analogous to the low prevalence of the heterozygous MLS deletion in humans.
We believe the spectrum of clinical features seen in females with MLS and the paucity of male patients are consistent with significant involvement of HCCS.
This supports the notion that functional absence of the MLS gene caused by inactivation of the normal X chromosome plays a pivotal role in the development of MLS in patients with Xp22 monosomy.
The human holocytochrome c-type synthetase (HCCS) gene is located on Xp22.3 and is one of the genes identified in a 450-Kb region deleted in the neurodevelopmental disorder microphthalmia with linear skin defects.
NDUFB11, a component of mitochondrial complex I, is a relatively small integral membrane protein, belonging to the "supernumerary" group of subunits, but proved to be absolutely essential for the assembly of an active complex I. Mutations in the X-linked nuclear-encoded NDUFB11 gene have recently been discovered in association with two distinct phenotypes, i.e. microphthalmia with linear skin defects and histiocytoid cardiomyopathy.
Downregulation of the COX7B ortholog (cox7B) in medaka (Oryzias latipes) resulted in microcephaly and microphthalmia that recapitulated the MLS phenotype and demonstrated an essential function of complex IV activity in vertebrate CNS development.
Future molecular studies in karyotypically normal female MLS patients to detect submicroscopic rearrangements including the ARHGAP6 gene as well as mutation screening of ARHGAP6 in patients with no obvious chromosomal rearrangements will clarify the role of this gene in MLS syndrome.
MLS is a translocation-related sarcoma (TRS) related to the chromosomal translocation t(12:16) (q13:p11), producing the FUS-CHOP oncoprotein that constitutes one of the main targets of trabectedin in MLS patients.
Myxoid liposarcoma (MLS) is an aggressive soft-tissue tumor characterized by a specific reciprocal t(12;16) translocation resulting in expression of the chimeric FUS-DDIT3 fusion protein, an oncogenic transcription factor.
MLS is a translocation-related sarcoma (TRS) related to the chromosomal translocation t(12:16) (q13:p11), producing the FUS-CHOP oncoprotein that constitutes one of the main targets of trabectedin in MLS patients.
Here we show, using an unbiased functional genomic approach, that FUS-DDIT3-expressing mesenchymal stem cells and MLS cell lines are dependent on YAP1, a transcriptional co-activator and central effector of the Hippo pathway involved in tissue growth and tumorigenesis, and that increased YAP1 activity is a hallmark of human MLS Mechanistically, FUS-DDIT3 promotes YAP1 expression, nuclear localization, and transcriptional activity and physically associates with YAP1 in the nucleus of MLS cells.
Myxoid liposarcoma (MLS) is an aggressive soft-tissue tumor characterized by a specific reciprocal t(12;16) translocation resulting in expression of the chimeric FUS-DDIT3 fusion protein, an oncogenic transcription factor.