A Novel Pathogenic Variant in the MN1 Gene in a Patient Presenting with Rhombencephalosynapsis and Craniofacial Anomalies, Expanding MN1 C-terminal Truncation Syndrome

Meningioma-1 is a transcription activator that regulates mammalian palate development and is required for appropriate osteoblast proliferation, motility, differentiation, and function. Microdeletions involving the MN1 gene have been linked to syndromes including craniofacial anomalies, such as Toriello-Carey syndrome. Recently, truncating variants in the C-terminal portion of the MN1 transcriptional factor have been linked to a characteristic and distinct phenotype presenting with craniofacial anomalies and partial rhombencephalosynapsis, a rare brain malformation characterized by midline fusion of the cerebellar hemispheres with partial or complete loss of the cerebellar vermis. It has been called MN1 C-terminal truncation (MCTT) syndrome or CEBALID (Craniofacial defects, dysmorphic Ears, Brain Abnormalities, Language delay, and Intellectual Disability) and suggested to be caused by dominantly acting truncated protein MN1 instead of haploinsufficiency. As a proto-oncogene, MN1 is also involved in familial meningioma. In this study, we present a novel case of MCTT syndrome in a female patient presenting with craniofacial anomalies and rhombencephalosynapsis, harboring a de novo pathogenic variant in the MN1 gene: c.3686_3698del, p.(Met1229Argfs*87).

Expanding the Phenotypic Spectrum of Alazami Syndrome: Two Unrelated Spanish Families

Alazami syndrome is a rare disorder with an autosomal recessive inheritance caused by pathogenic biallelic variants in the LARP7 gene. Clinically, it is mainly characterized by short stature, intellectual disability, and dysmorphic facial features. However, the phenotype is not yet well-defined because less than 50 cases have been described to date. Here, we report three new patients from two unrelated Spanish families who, in addition to the defined features of Alazami syndrome, also exhibit unique features that broaden the phenotypic spectrum of the syndrome. Moreover, we describe the novel frameshift variant c.690_699delins27 in the LARP7 gene, in which loss of function is a known mechanism of Alazami syndrome.

Hereditary cerebral small vessel disease: Assessment of a HTRA1 variant using protein stability predictors and 3D modelling

Cerebral autosomal recessive arteriopathy with subcortical infarcts and leukoencephalopathy (CARASIL) is an autosomal recessive vascular disorder caused by biallellic variants in HTRA1. Recently, it has been reported that several heterozygous mutations in HTRA1 are responsible for a milder late-onset cerebral small vessel disease (CSVD) with an autosomal dominant pattern of inheritance. The majority of them are missense that affects the Htr1A protease activity due to a dominant-negative effect caused by defective trimerization or monomer activation. The molecular mechanism related to the structural destabilization of the protein supports the practical utility of integrating computational stability predictors to prioritize candidate variants in this gene. In this work, we report a family with several members diagnosed with subcortical ischemic events and progressive cognitive impairment caused by the novel c.820C > G, p.(Arg274Gly) heterozygous variant in HTRA1 segregating in an autosomal dominant manner and propose its molecular mechanism by a three-dimensional model of the protein's structure.

Biallelic variants in genes previously associated with dominant inheritance: CACNA1A, RET and SLC20A2

A subset of families with co-dominant or recessive inheritance has been described in several genes previously associated with dominant inheritance. Those recessive families displayed similar, more severe, or even completely different phenotypes to their dominant counterparts. We report the first patients harboring homozygous disease-related variants in three genes that were previously associated with dominant inheritance: a loss-of-function variant in the CACNA1A gene and two missense variants in the RET and SLC20A2 genes, respectively. All patients presented with a more severe clinical phenotype than the corresponding typical dominant form. We suggest that co-dominant or recessive inheritance for these three genes could explain the phenotypic differences from those documented in their cognate dominant phenotypes. Our results reinforce that geneticists should be aware of the possible different forms of inheritance in genes when WES variant interpretation is performed. We also evidence the need to refine phenotypes and inheritance patterns associated with genes in order to avoid failures during WES analysis and thus, raising the WES diagnostic capacity in the benefit of patients.

Pathological and sub-pathological changes in European rabbit bones: Two reference cases to be applied to the analysis of archaeological assemblages

OBJECTIVE

To provide prevalence data for future comparative analysis of the health status of rabbits (Oryctolagus cuniculus) accumulated in the archaeological record.

MATERIALS

Two contrasting assemblages were analysed for pathological and sub-pathological changes: 1) an assemblage of domestic modern rabbit bones; and 2) a non-anthropogenic accumulation of archaeological rabbit remains.

METHODS

The lesions observed macroscopically, under magnification, and radiographically in both assemblages are quantified and described.

RESULTS

In the first assemblage, pathological and sub-pathological changes mostly affected the lower limb bones and primarily took two forms: diaphyseal periosteal proliferation and hypervascularised distal physes. Differential diagnosis of the periosteal proliferation suggests that pododermatitis is the most probable cause. In the second assemblage fractures were the most common lesions, but isolated examples of hypervascularised physes, periosteal proliferation, and musculo-skeletal stress markers were also identified. The pathological changes recorded is typical of a naturally-accumulated population of wild rabbits.

CONCLUSIONS

The prevalence of pathological and sub-pathological skeletal changes in the rabbits, and thus their health status, are closely related to living conditions. This study demonstrates the value of systematically recording pathologies in rabbit bones.

SIGNIFICANCE

We contribute new data to help understand rabbit interactions with humans in the past and also the environment they inhabited.

LIMITATIONS

Working with modern samples frequently means only incomplete skeletons are available for study. In these cases lesion prevalence always needs to be interpreted with caution.

SUGGESTIONS FOR FURTHER RESEARCH

Paleopathological studies of rabbit remains are remarkable for their absence. Further exhaustive research in this area is advised.

First female with Allan-Herndon-Dudley syndrome and partial deletion of X-inactivation center

Allan-Herndon-Dudley is an X-linked recessive syndrome caused by pathogenic variants in the SLC16A2 gene. Clinical manifestations are a consequence of impaired thyroid metabolism and aberrant transport of thyroid hormones to the brain. Carrier females are generally asymptomatic and may show subtle symptoms of the disease. We describe a female with a complete Allan-Herndon-Dudley phenotype, carrying a de novo 543-kb deletion of the X chromosome. The deletion encompasses exon 1 of the SLC16A2 gene and JPX and FTX genes; it is known that the latter two genes participate in the X-inactivation process upregulating XIST gene expression. Subsequent studies in the patient demonstrated the preferential expression of the X chromosome with the JPX and FTX deletion.

First patient with mosaic NOTCH3 gene pathogenic variant. Unrevealed mosaicisms and importance of their detection

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is an inherited small vessel disease caused predominantly by pathogenic variants in NOTCH3 gene. Neither germline nor somatic mosaicism has been previously published in NOTCH3 gene. CADASIL is inherited in an autosomal dominant manner; only rare cases have been associated with de novo pathogenic variants. Mosaicism is more common than previously thought because mosaic variants often stay unrevealed. An apparently de novo variant might actually be a consequence of a parental mosaicism undetectable with Sanger sequencing, especially in the case of low grade mosaicism. Parental testing by sensitive tools like deep targeted next-generation sequencing (NGS) analysis could detect cases of unrevealed medium or low level mosaicism in patients tested by Sanger sequencing. Here, we report the first patient with mosaic NOTCH3 gene pathogenic variant to our knowledge; the allelic fraction in the leucocyte DNA was low (13%); the pathogenic variant was inhered by his two daughters. The patient was diagnosed by deep targeted NGS analysis after studying his two affected daughters. This report highlights the importance of parental testing by sensitive tools like deep targeted NGS analysis. Detection of mosaicism is of great importance for diagnosis and adequate family genetic counseling.

First report of Stegomyia aegypti (= Aedes aegypti) in Mexico City, Mexico

Stegomyia aegypti (= Aedes aegypti) (Diptera: Culicidae) is a species of mosquito that is currently widespread in Mexico. Historically, the mosquito has been distributed across most tropical and subtropical areas lower than 1700 m a.s.l. Currently, populations that are found at higher altitudes in regions with cold and dry climates suggest that these conditions do not limit the colonization and population growth of S. aegypti. During a survey of mosquitoes in September 2015, larvae of S. aegypti mosquitoes were found in two different localities in Mexico City, which is located at about 2250 m a.s.l. Mexico City is the most populous city in Mexico and has inefficient drainage and water supply systems. These factors may result in the provision of numerous larval breeding sites. Mosquito monitoring and surveillance are now priorities for the city.

Prognostic factors associated with mortality in patients with severe trauma: from prehospital care to the Intensive Care Unit

OBJECTIVE

To identify factors related to mortality in adult trauma patients, analyzing the clinical, epidemiological and therapeutic characteristics at the pre-hospital levels, in the Emergency Care Department and in Intensive Care.

DESIGN

A retrospective, longitudinal descriptive study was carried out. Statistical analysis was performed using SPSS, MultBiplot and data mining methodology.

SETTING

Adult multiple trauma patients admitted to the Salamanca Hospital Complex (Spain) from 2006 to 2011.

MAIN VARIABLES OF INTEREST

Demographic variables, clinical, therapeutic and analytical data from the injury site to ICU admission. Evolution from ICU admission to hospital discharge.

RESULTS

A total of 497 patients with a median age of 45.5 years were included. Males predominated (76.7%). The main causes of injury were traffic accidents (56.1%), precipitation (18.4%) and falls (11%). The factors with the strongest association to increased mortality risk (P<.05) were age > 65 years (OR 3.15), head injuries (OR 3.1), pupillary abnormalities (OR 113.88), level of consciousness according to the Glasgow Coma Scale ≤ 8 (OR 12.97), and serum lactate levels > 4 mmol/L (OR 9.7).

CONCLUSIONS

The main risk factors identified in relation to the prognosis of trauma patients are referred to the presence of head injuries. Less widely known statistical techniques such as data mining or MultBiplot also underscore the importance of other factors such as lactate concentration. Trauma registries help assess the healthcare provided, with a view to adopting measures for improvement.

Current immunity markers in insect ecological immunology: assumed trade-offs and methodological issues

The field of ecological immunology currently relies on using a number of immune effectors or markers. These markers are usually used to infer ecological trade-offs (via conflicts in resource allocation), though physiological nature of these markers remains elusive. Here, we review markers frequently used in insect evolutionary ecology research: cuticle darkening, haemocyte density, nodule/capsule formation, phagocytosis and encapsulation/melanization via use of nylon filaments and beads, phenoloxidase activity, nitric oxide production, lysozyme and antimicrobial peptide production. We also provide physiologically based information that may shed light on the probable trade-offs inferred when these markers are used. In addition, we provide a number of methodological suggestions to improve immune marker assessment.

Application of QF-PCR for the prenatal assessment of discordant monozygotic twins for fetal sex

OBJECTIVE

To establish the utility of quantitative fluorescent polymerase chain reaction (QF-PCR) in order to determine the zygosity of multiple pregnancies, as well as to define the origin of the most frequent aneuploidies in amniotic fluid samples.

METHODS

We describe the case of a monochorionic (MC) diamniotic (DA) pregnancy with phenotypically discordant twins (nuchal cystic hygroma and non-immune hydrops in twin A and no anomalies in twin B). QF-PCR was performed for rapid prenatal diagnosis in uncultured amniocytes and subsequently in cultured cells. Polymorphic markers for chromosomes X, Y, 13, 18 and 21 were used for determination of zygosity as well as sex chromosome aneuploidy.

RESULTS

Twin A showed a Turner Syndrome (TS) mosaicism pattern by QF-PCR in uncultured amniocytes. The monozygotic origin of the pregnancy was determined. Interphase fluorescence in situ hybridization (I-FISH) in this sample showed a mosaicism X0/XY (83/17%). Cytogenetic analysis revealed a 45,X0 karyotype in twin A and a 46,XY karyotype in twin B.

CONCLUSIONS

QF-PCR is a reliable tool for the determination of the zygosity independently of the chorionicity and the fetal sex in case of twin pregnancy. Testing both direct and cultured cells can provide useful results for genetic counselling in chromosomal mosaicisms.

Chromosomal anomalies in patients with short stature

BACKGROUND

The incidence of chromosomal anomalies in patients with short stature (SS) was studied in order to determine the value of routine karyotyping in this population.

METHODS

This study was a retrospective evaluation of 972 patients (719 females and 253 males) with SS. Chromosomal analysis was performed on cultured peripheral lymphocytes.

RESULTS

The incidence of chromosome aberrations in males was 2.77% (7/253) and in females 9.8% (71/719). Several groups were made according to clinical features and familial antecedents of SS. We observed different incidence rates of chromosomal anomalies among groups of patients, mainly in females. The incidence in the group without familial antecedents was 18.89%, however, in females with familial antecedents it was 4.45%. In females with isolated SS we detected karyotype anomalies in the 3.98%, while in patients with phenotypic features, amenorrhoea and SS the incidence was 77.78%. In females the most frequent anomaly was Turner syndrome, present in 55 patients (77.46%).

CONCLUSION

Karyotype analysis is recommended for all girls with unexplained SS and associated abnormalities. In females with isolated SS a cost-benefit analysis must be done in each case.

SRY-positive 46,XX male with cryptorchidism as the only presenting clinical feature

The SRY gene, located on the short arm of the Y chromosome, is responsible for differentiation of the testis from the undifferentiated gonad. We report a 4-year-old patient with male phenotype and female karyotype (46,XX) with cryptorchidism as the only presenting clinical abnormality. Fluorescent in situ hybridization analysis, using Y- and X-specific (whole chromosome painting WCP Y WCP X) DNA and SRY probes, detected a small Y chromosome fragment, including the SRY gene, transferred to the short arm of the X chromosome.