Identification of STAC3 variants in non-Native American families with overlapping features of Carey–Fineman–Ziter syndrome and Moebius syndrome

Horstick et al. (2013) previously reported a homozygous p.Trp284Ser variant in STAC3 as the cause of Native American myopathy (NAM) in 5 Lumbee Native American families with congenital hypotonia and weakness, cleft palate, short stature, ptosis, kyphoscoliosis, talipes deformities, and susceptibility to malignant hyperthermia (MH). Here we present two non-Native American families, who were found to have STAC3 pathogenic variants. The first proband and her affected older sister are from a consanguineous Qatari family with a suspected clinical diagnosis of Carey–Fineman–Ziter syndrome (CFZS) based on features of hypotonia, myopathic facies with generalized weakness, ptosis, normal extraocular movements, cleft palate, growth delay, and kyphoscoliosis. We identified the homozygous c.851G>C;p.Trp284Ser variant in STAC3 in both sisters. The second proband and his affected sister are from a non-consanguineous, Puerto Rican family who was evaluated for a possible diagnosis of Moebius syndrome (MBS). His features included facial and generalized weakness, minimal limitation of horizontal gaze, cleft palate, and hypotonia, and he has a history of MH. The siblings were identified to be compound heterozygous for STAC3 variants c.851G>C;p.Trp284Ser and c.763_766delCTCT;p.Leu255IlefsX58. Given the phenotypic overlap of individuals with CFZS, MBS, and NAM, we screened STAC3 in 12 individuals diagnosed with CFZS and in 50 individuals diagnosed with MBS or a congenital facial weakness disorder. We did not identify any rare coding variants in STAC3. NAM should be considered in patients presenting with facial and generalized weakness, normal or mildly abnormal extraocular movement, hypotonia, cleft palate, and scoliosis, particularly if there is a history of MH.

from Genetics via xlomafota13 on Inoreader http://ift.tt/2ubfnxH
via IFTTT

Skewed X-inactivation in a family with DLG3-associated X-linked intellectual disability

Mutations in DLG3 are a rare cause of non-syndromic X-linked intellectual disability (XLID) (MRX90, OMIM *300189). Only ten DLG3 mutations have been reported to date. The majority of female heterozygous mutation carriers was healthy and had random X-inactivation patterns. We report on an XLID family with a novel DLG3 mutation. The 12-year-old male index patient had moderate intellectual disability (ID) and dysmorphic features. The mutation was also present in four female relatives. A maternal aunt had moderate ID and significantly skewed X-inactivation favorably inactivating the normal DLG3 allele. The proband's healthy mother also had skewed X-inactivation but in the opposite direction (i.e., inactivation of the mutated allele). Two other female relatives had intermediate cognitive phenotypes and random X-inactivation. This family broadens the mutational and phenotypical spectrum of DLG3-associated XLID and demonstrates that heterozygous female mutation carriers can be as severely affected as males. Reports of additional families will be needed to elucidate the causes of unfavorable skewing in female XLID patients.

from Genetics via xlomafota13 on Inoreader http://ift.tt/2urBIlO
via IFTTT

A human case of SLC35A3-related skeletal dysplasia

Researchers have identified a subset of Holstein having a range of skeletal deformities, including vertebral anomalies, referred to as complex vertebral malformation due to mutations in the SLC35A3 gene. Here, we report the first case in humans of SLC35A3-related vertebral anomalies. Our patient had prenatally diagnosed anomalous vertebrae, including butterfly, and hemivertebrae throughout the spine, as well as cleft palate, micrognathia, patent foramen ovale, patent ductus arteriosus, posterior embryotoxon, short limbs, camptodactyly, talipes valgus, rocker bottom feet, and facial dysmorphism including proptosis, nevus flammeus, and a cupped left ear. Clinical exome sequencing revealed a novel missense homozygous mutation in SLC35A3. Follow-up biochemical analysis confirmed abnormal protein glycosylation, consistent with a defective Golgi UDP-GlcNAc transporter, validating the mutations. Congenital disorders of glycosylation, including SLC35A3-CDG, can present as a wide phenotypic spectrum, including skeletal dysplasia. Previously reported patients with SLC35A3-CDG have been described with syndromic autism, epilepsy, and arthrogryposis.

from Genetics via xlomafota13 on Inoreader http://ift.tt/2uaANuP
via IFTTT

A novel genetic syndrome with STARD9 mutation and abnormal spindle morphology

Intellectual disability (ID) is one of neurodevelopmental disorders characterized by serious defects in both intelligence and adaptive behavior. Although it has been suggested that genetic aberrations associated with the process of cell division underlie ID, the cytological evidence for mitotic defects in actual patient's cells is rarely reported. Here, we report a novel mutation in the STARD9 (also known as KIF16A) gene found in a patient with severe ID, characteristic features, epilepsy, acquired microcephaly, and blindness. Using whole-exome sequence analysis, we sequenced potential candidate genes in the patient. We identified a homozygous single-nucleotide deletion creating a premature stop codon in the STARD9 gene. STARD9 encodes a 4,700 amino acid protein belonging to the kinesin superfamily. Depletion of STARD9 or overexpression of C-terminally truncated STARD9 mutants were known to induce spindle assembly defects in human culture cells. To determine cytological features in the patient cells, we isolated lymphoblast cells from the patient, and performed immunofluorescence analysis. Remarkably, mitotic defects, including multipolar spindle formation, fragmentation of pericentriolar materials and centrosome amplification, were observed in the cells. Taken together, our findings raise the possibility that controlled expression of full-length STARD9 is necessary for proper spindle assembly in cell division during human development. We propose that mutations in STARD9 result in abnormal spindle morphology and cause a novel genetic syndrome with ID.

from Genetics via xlomafota13 on Inoreader http://ift.tt/2urdGrf
via IFTTT

ALG13-CDG in a male with seizures, normal cognitive development, and normal transferrin isoelectric focusing

ALG13-CDG has been recently discovered as a disorder of severe developmental, intellectual and speech disability, microcephaly, visual abnormalities, seizures, hepatomegaly, coagulation abnormalities, and abnormal serumtransferrin isoelectric focusing in serum. A male with seizures, delayed motor, and speech development, but normal cognition carried a hemizygous, predicted pathogenic ALG13 variant (p.E463G). N-glycosylation studies in plasma were normal. ICAM-1 expression was decreased in patient fibroblasts, supporting the variant's pathogenicity. Adding D-galactose to the patient's fibroblast culture increased ICAM-1 expression in vitro, offering a potential treatment option in ALG13-CDG. The present report is a new example for an N-glycosylation disorder, that may present with normal transferrin isoform analysis, and also demonstrates, that CDG type I patients can have normal cognitive development.

from Genetics via xlomafota13 on Inoreader http://ift.tt/2uaG717
via IFTTT

Wake County EMS driver training

Operating an ambulance on the highway is usually fairly straight forward. But navigating tight neighborhoods while patients are being cared for in the back can be a little tricky. Academy members spend time exercising vehicle operations drills.

from EMS via xlomafota13 on Inoreader http://ift.tt/2wrX5EZ
via IFTTT

Wake County EMS driver training

Operating an ambulance on the highway is usually fairly straight forward. But navigating tight neighborhoods while patients are being cared for in the back can be a little tricky. Academy members spend time exercising vehicle operations drills.

from EMS via xlomafota13 on Inoreader http://ift.tt/2wrX5EZ
via IFTTT