ARL6IP6, a susceptibility locus for ischemic stroke, is mutated in a patient with syndromic Cutis Marmorata Telangiectatica Congenita

Optical coherence tomography angiography in pediatric ocular cutis marmorata telangiectatica congenita: A case series

Purpose

To report 2 cases of enlarged foveal avascular zone (FAZ) on optical coherence angiography (OCTA) imaging in pediatric patients with cutis marmorata telangiectatica congenita (CMTC).

Observations

A 10-week-old female and a 3-year-old male diagnosed with CMTC presented for retinal examination. Both had peripheral avascularity on fluorescein angiography (FA) and enlargement of the FAZ on OCTA in both eyes.

Conclusions and Importance

Pediatric patients with CMTC should undergo ocular evaluation with not only FA, but also OCTA to more robustly evaluate the affected retina in this rare disease.

Assessing Genomic Diversity and Productivity Signatures in Dianzhong Cattle by Whole-Genome Scanning

Dianzhong cattle is a classic Chinese indigenous cattle breed with historical records dating back to 200 BC. But with its genomic differences having not been clearly elucidated, the quest for genomic characterization will be an essential step towards understanding the genomic basis of productivity and adaptation to survival under Chinese farming systems. Here we compared 10 Dianzhong cattle (four newly sequenced and six downloaded) with 29 published genomes of three underlying ancestral populations (Chinese zebu, Indian zebu, and Yanbian cattle) to characterize the genomic variations of Dianzhong cattle. Dianzhong cattle has a high nucleotide diversity (0.0034), second only to Chinese zebu. Together with analyses of linkage disequilibrium decay and runs of homozygosity, Dianzhong cattle displayed higher genomic diversity and weaker artificial selection compared with Yanbian cattle. From a selective sweep analysis by four methods (Fst, π-ratio, XP-CLR, and XP-EHH), the positive selective signals were mainly manifested in candidate genes and pathways related to heat resistance, growth and development, fat deposition, and male reproduction. Missense mutations were detected in candidate genes, SDS (c.944C > A and p.Ala315Glu), PDGFD (c.473A > G and p.Lys158Arg), and DDX4 (rs460251486, rs722912933, and rs517668236), which related to heat resistance, fat deposition, and spermatogenesis, respectively. Our findings unravel, at the genome-wide level, the unique diversity of Dianzhong cattle while emphasizing the opportunities for improvement of livestock productivity in further breeding programs.

Identification of new transmembrane proteins concentrated at the nuclear envelope using organellar proteomics of mesenchymal cells

The double membrane nuclear envelope (NE), which is contiguous with the ER, contains nuclear pore complexes (NPCs) – the channels for nucleocytoplasmic transport, and the nuclear lamina (NL) – a scaffold for NE and chromatin organization. Since numerous human diseases linked to NE proteins occur in mesenchyme-derived cells, we used proteomics to characterize NE and other subcellular fractions isolated from mesenchymal stem cells and from adipocytes and myocytes. Based on spectral abundance, we calculated enrichment scores for proteins in the NE fractions. We demonstrated by quantitative immunofluorescence microscopy that five little-characterized proteins with high enrichment scores are substantially concentrated at the NE, with Itprip exposed at the outer nuclear membrane, Smpd4 enriched at the NPC, and Mfsd10, Tmx4, and Arl6ip6 likely residing in the inner nuclear membrane. These proteins provide new focal points for studying the functions of the NE. Moreover, our datasets provide a resource for evaluating additional potential NE proteins.

Cutis marmorata telangiectatica congenita: a focus on its diagnosis, ophthalmic anomalies, and possible etiologic factors

Purpose: Cutis marmorata telangiectatica congenita (CMTC) is a rare congenital disorder typified by localized or generalized cutaneous vascular anomalies, which dissipate over time. We review the diagnostic approach to CMTC and present a comprehensive examination of its ocular manifestations. Additionally, we offer recommendations for the ophthalmologic workup for patients with CMTC. Finally, we examine the possible causes of CMTC and summarize the current efforts to establish an etiologic mechanism for this disease.Methods: Thirty-three published cases of CMTC with ocular anomalies are examined in detail.Results: CMTC is diagnosed based on a specific set of congenital cutaneous symptoms, principally congenital reticular erythema that is unresponsive to local warming and absence of venectasia within the skin lesions. Ocular findings are not currently employed in this diagnostic process, likely due to an incomplete understanding into their presentation, frequency, and natural history. We show that the majority of ophthalmic manifestations are congenital, with glaucoma and posterior segment anomalies, consisting of retinal perfusion defects and vascular abnormalities, as the most frequently reported findings. Typical ophthalmic medical and surgical interventions appear to be effective for management of these CMTC-related pathology. Unfortunately, the etiology and pathophysiology of CMTC remains unknown, which obfuscates efforts to identify, examine, and initiate treatment in patients.Conclusions: While the ophthalmic community has traditionally viewed glaucoma as the classic ocular anomaly of CMTC, this dataset advocates for the prompt investigation of posterior segment abnormalities as well. However, our understanding of CMTC's ocular anomalies is complicated by a lack of reporting and/or incomplete (or nonexistent) ophthalmic examinations, and we strongly encourage comprehensive ophthalmic examinations for all CMTC patients at the time of diagnosis, followed by appropriate screening and surveillance throughout life. We believe these recommendations will spur additional data and disease insights that may be useful for future refinements to CMTC diagnostic algorithms.

Cutis marmorata telangiectatica congenita: a literature review

Background

Cutis marmorata telangiectatica congenita (CMTC) is a rare capillary malformation characterised by persistent reticulated marbled erythema. It tends to be associated with cutaneous atrophy, ulcerations and body asymmetry. CMTC is usually reported to be a benign condition; however, associated anomalies are not rare. Here, we have compiled information on published CMTC patients with the aim to evaluate the proposed diagnostic criteria by Kienast et al. and address the clinical manifestations, associated anomalies, differential diagnoses, management and prognosis. Our review is based on a search of the PubMed database which retrieved studies between 1922 and April 2019. The search yielded 148 original articles with a total of 485 patients.

Results

Of the identified patients, 24.5% had generalised CMTC, 66.8% had localised and 8.7% had a non-specified distribution of CMTC. Associated anomalies were observed in 42.5% of patients, predominantly body asymmetry and neurological defects like seizure and developmental delay. Fewer patients (10.1%) had ophthalmological defects, usually glaucoma. The major criterium “absence of venectasia” was not met in 20.4% of patients.

Conclusion

We suggest that children with CMTC should be referred to an ophthalmologist for regular follow-up, and children with CMTC affecting the legs should be monitored for leg length discrepancy throughout the growth period. Furthermore, we suggest reconsideration of the major criterium “absence of venectasia” from the proposed diagnostic criteria, and instead include body asymmetry.

Ocular Manifestations of Cutis Marmorata Telangiectatica Congenita

PURPOSE

To describe the range of ocular manifestations in cutis marmorata telangectatica congenita (CMTC).

DESIGN

Multicenter, retrospective, nonconsecutive case series.

PARTICIPANTS

Patients with a diagnosis of CMTC referred for ophthalmologic evaluation between January 1, 2015, and December 31, 2018.

METHODS

Evaluation of ocular findings at presentation, systemic manifestations suggestive of a diagnosis of CMTC, genetic testing, and visual outcomes after treatment.

MAIN OUTCOME MEASURES

Visual acuity, findings on ophthalmoscopy, and results of fluorescein angiography.

RESULTS

Nine patients with CMTC diagnosed clinically based on stereotypical cutaneous vascular malformations were included. The median age at presentation was 8 weeks (range, 2 weeks-4 years). Six patients were female and 3 were male. Avascular retina was identified on dilated fundus examination, fluorescein angiography, or both in 11 eyes of 6 patients. Retinal neovascularization was present bilaterally in 2 patients at presentation. One patient demonstrated retinal venous tortuosity, and another patient showed mild straightening of nasal retinal vessels in both eyes. Two patients (2 eyes) demonstrated retinal detachment (RD). Both were managed surgically. One infant demonstrated RD, whereas the other child showed extensive neovascularization and later progressed to combined tractional-rhegmatogenous detachment. A unique constellation of lacy peripheral capillary anomalies with prominent terminal vascular bulbs was noted in 3 patients. Granular pigment abnormalities were noted in the macula in 5 patients. Two patients demonstrated glaucoma, 1 requiring surgical intervention. Two patients demonstrated features of Adams-Oliver syndrome, with genetic testing identifying a Notch1 mutation in 1 patient.

CONCLUSIONS

Retinal vascular abnormalities in CMTC may occur more frequently than recognized previously. Given the variability of ocular involvement and the potential for rapidly progressive retinal vascular abnormalities and development of RD, complete ophthalmologic evaluation including measurement of intraocular pressure, gonioscopy, dilated fundus examination, and fluorescein angiography is recommended in infants with suspected CMTC shortly after birth. The distinct pattern of lacy capillary anomalies with prominent terminal bulbs seen in CMTC has not been described in other syndromes of vascular dysgenesis. Therefore, ophthalmic examination may be a valuable method to distinguish CMTC from other disorders demonstrating similar dermatologic and systemic manifestations.

GWAS signals revisited using human knockouts

PurposeGenome-wide association studies (GWAS) have been instrumental to our understanding of the genetic risk determinants of complex traits. A common challenge in GWAS is the interpretation of signals, which are usually attributed to the genes closest to the polymorphic markers that display the strongest statistical association. Naturally occurring complete loss of function (knockout) of these genes in humans can inform GWAS interpretation by unmasking their deficiency state in a clinical context.MethodsWe exploited the unique population structure of Saudi Arabia to identify novel knockout events in genes previously highlighted in GWAS using combined autozygome/exome analysis.ResultsWe report five families with homozygous truncating mutations in genes that had only been linked to human disease through GWAS. The phenotypes observed in the natural knockouts for these genes (TRAF3IP2, FRMD3, RSRC1, BTBD9, and PXDNL) range from consistent with, to unrelated to, the previously reported GWAS phenotype.ConclusionWe expand the role of human knockouts in the medical annotation of the human genome, and show their potential value in informing the interpretation of GWAS of complex traits.

The Arab genome: Health and wealth

The 22 Arab nations have a unique genetic structure, which reflects both conserved and diverse gene pools due to the prevalent endogamous and consanguineous marriage culture and the long history of admixture among different ethnic subcultures descended from the Asian, European, and African continents. Human genome sequencing has enabled large-scale genomic studies of different populations and has become a powerful tool for studying disease predictions and diagnosis. Despite the importance of the Arab genome for better understanding the dynamics of the human genome, discovering rare genetic variations, and studying early human migration out of Africa, it is poorly represented in human genome databases, such as HapMap and the 1000 Genomes Project. In this review, I demonstrate the significance of sequencing the Arab genome and setting an Arab genome reference(s) for better understanding the molecular pathogenesis of genetic diseases, discovering novel/rare variants, and identifying a meaningful genotype-phenotype correlation for complex diseases.