Comprehensive prenatal diagnostics: Exome versus genome sequencing.

OBJECTIVE: This study aimed to assess the diagnostic yield of prenatal genetic testing using trio whole exome sequencing (WES) and trio whole genome sequencing (WGS) in pregnancies with fetal anomalies by comparing the results with conventional chromosomal microarray (CMA) analysis. METHODS: A total of 40 pregnancies with fetal anomalies or increased nuchal translucency (NT ≥ 5 mm) were included between the 12th and 21st week of gestation. Trio WES/WGS and CMA were performed in all cases. RESULTS: The trio WES/WGS analysis increased the diagnostic yield by 25% in cases with negative CMA results. Furthermore, all six chromosomal aberrations identified by CMA were independently detected by WES/WGS analysis. In total, 16 out of 40 cases obtained a genetic sequence variant, copy number variant, or aneuploidy explaining the phenotype, resulting in an overall WES/WGS diagnostic yield of 40%. WES analysis provided a more reliable identification of mosaic sequence variants than WGS because of its higher sequencing depth. CONCLUSIONS: Prenatal WES/WGS proved to be powerful diagnostic tools for fetal anomalies, surpassing the diagnostic yield of CMA. They have the potential to serve as standalone methods for prenatal diagnosis. The study highlighted the limitations of WGS in accurately detecting mosaic variants, which is particularly relevant when analyzing chorionic villus samples.

Whole genome sequencing and disease pattern in patients with juvenile polyposis syndrome: a nationwide study.

Juvenile polyposis syndrome (JPS) is a hereditary hamartomatous polyposis syndrome characterized by gastrointestinal juvenile polyps and increased risk of gastrointestinal cancer. Germline pathogenic variants are detected in SMAD4 or BMPR1A, however in a significant number of patients with JPS, the etiology is unknown. From Danish registers, and genetic department and laboratories, we identified all patients in Denmark with a clinical diagnosis of JPS and/or a pathogenic variant in BMPR1A or SMAD4. In patients where no variant had been detected, we performed genetic analysis, including whole genome sequencing. We collected clinical information on all patients to investigate the phenotypic spectrum. Sixty-six patients (mean age 40 years) were included of whom the pathogenic variant was unknown in seven patients. We detected a pathogenic variant in SMAD4 or PTEN in additional three patients and thus ≈ 95% of patients had a pathogenic germline variant. Endoscopic information was available in fifty-two patients (79%) and of these 31 (60%) fulfilled the clinical criteria of JPS. In 41 patients (79%), other types of polyps than juvenile had been removed. Our results suggest that almost all patients with a clinical diagnosis of JPS has a pathogenic variant in mainly BMPR1A, SMAD4, and more rarely PTEN. However, not all patients with a pathogenic variant fulfil the clinical criteria of JPS. We also demonstrated a wide clinical spectrum, and that the histopathology of removed polyps varied.

Distinct gastric phenotype in patients with pathogenic variants in SMAD4: A nationwide cross-sectional study.

Background and study aims In most patients with juvenile polyposis Syndrome, it is possible to detect a pathogenic germline variant in SMAD4 or BMPR1A . It is well known that patients with a pathogenic variant in SMAD4 have a higher risk of gastric polyposis and gastric cancer compared to BMPR1A carriers, but the natural history of gastric involvement is poorly described. We aimed to systematically review endoscopic and histopathological gastric findings in Danish patients with pathogenic variants in SMAD4. Patients and methods This was a retrospective, cross-sectional study including endoscopic and histological gastric findings in all known Danish patients with pathogenic variants in SMAD4 . The patients were identified by data from various registries as well as from clinical genetic departments and laboratories. Results We identified 41 patients (2-72 years) with a pathogenic SMAD4 variant . In 31 patients, we were able to retrieve information on upper gastrointestinal endoscopy. Eighty-seven percent had at least one gastric abnormality including erythema (72 %) and edema (72 %). Half of the patients also had vulnerability of the mucosa and 68 % had gastric polyposis. An increasing frequency of abnormalities were observed with increasing age. Gastric cancer was diagnosed in 5 % of the cases and 22 % had a gastrectomy mainly because of massive polyposis. Conclusions This study showed that most patients with pathogenic SMAD4 variants have a distinct phenotype of the gastric mucosa, and with an increasing severity in the elderly patients. These findings provide new insights into the natural history of gastric manifestations in patients with pathogenic SMAD4 variants.

[Cutaneous capillary malformations with cerebral implementation].

Capillary malformations - arteriovenous malformation, hereditary hemorrhagic telangiectasia and Sturge-Weber syndrome - are rare diseases in which cutaneous capillary malformations (CM) may be associated with cerebral vascular malformations. The clinical presentation of each disease is described with focus on how to distinguish them in the clinic and differential diagnoses are listed. This review finds that upon thorough and careful examination of patients, cutaneous CM might be a diagnostic hallmark for underlying disease and therefore a significant clinical observation.

Novel truncating variants in FGD1 detected in two Danish families with Aarskog-Scott syndrome and myopathic features.

Aarskog-Scott syndrome (AAS) is a developmental disorder, caused by disease-causing hemizygous variants in the FGD1 gene. AAS is characterized by dysmorphic features, genital malformation, skeletal anomalies, and in some cases, intellectual disability and behavioral difficulties. Myopathy has only been reported once in two affected siblings diagnosed with AAS. Only few adult cases have been reported. This article reports four adults with AAS (three male cases and one female carrier) from two unrelated Danish families, all males presented with variable features suggestive of myopathy. All four carried novel hemizygous pathogenic variants in the FGD1 gene; one family presented with the c.2266dup, p.Cys756Leufs*19 variant while the c.527dup; p.Leu177Thrfs*40 variant was detected in the second family. All males had some mild myopathic symptoms or histological abnormalities. Case 1 had the most severe myopathic phenotype with prominent proximal muscular fatigue and exercise intolerance. In addition, he had multiple deletions of mtDNA and low respiratory chain activity. His younger nephew, case 3, had difficulties doing sports in his youth and had a mildly abnormal muscle biopsy and relatively decreased mitochondrial enzyme activity. The singular case from family 2 (case 4), had a mildly myopathic muscle biopsy, but no overt myopathic symptoms. Our findings suggest that myopathic involvement should be considered in AAS.

Capillary Malformation-arteriovenous Malformation Type 2: A Case Report and Review.

Capillary malformation-arteriovenous malformation syndrome is a rare genodermatosis with cutaneous capillary malformations and a risk of associated fast-flow malformations. We describe here a four-generation family with a novel heterozygous pathogenic variant in the EPHB4 gene (NM_004444.5 (EPHB4): c.2224G>C, p.(Ala742Pro)). A review of the literature retrieved 127 patients with capillary malformation-arteriovenous malformation syndrome and confirmed variants in EPHB4. Multiple capillary malformations were present in 114 (89.76%) patients, and 12 (9.44%) patients had a solitary capillary malformation. Arteriovenous malformations/fistulas were present in 23 (18.1%) patients, and were located within the central nervous system in 5 (3.9%) patients. Not all papers included description of epistaxis. Telangiectasias were reported in 28 (22%) patients, and Bier spots were described in 20 (15.7%) patients. The clinical characteristics of capillary malformation-arteriovenous malformation syndrome are diverse and often discrete, which can make it difficult to distinguish capillary malformation-arteriovenous malformation syndrome from hereditary haemorrhagic telangiectasia.

Prenatal cases with rare RIT1 variants causing severe fetal hydrops and death.

We describe two clinical prenatal cases with rare de novo RIT1 variants, which showed more severe clinical manifestations than other Noonan Syndrome genotypes, resulting in fetal death. Extra attention is recommended when these variants are detected.

[Screening for cerebral arteriovenous malformations in patients with hereditary haemorrhagic telangiectasia].

Patients with hereditary haemorrhagic telangiectasia (HHT) are known to suffer from cerebral arteriovenous malformations (CAVMs). In this review, we explore existing literature for bleeding risk, interventional therapy and neuroradiological features in HHT-related CAVMs. Studies estimate the annual intracerebral haemorrhage rate of CAVMs in HHT patients to be 0.667-1.014%. The clinician must balance bleeding risk and the non-negligible procedural risks of interventional therapy. We recommend, in agreement with European guidelines, that screening of asymptomatic HHT patients should only be carried out after careful information.

DOORS syndrome and a recurrent truncating ATP6V1B2 variant.

PURPOSE: Biallelic variants in TBC1D24, which encodes a protein that regulates vesicular transport, are frequently identified in patients with DOORS (deafness, onychodystrophy, osteodystrophy, intellectual disability [previously referred to as mental retardation], and seizures) syndrome. The aim of the study was to identify a genetic cause in families with DOORS syndrome and without a TBC1D24 variant. METHODS: Exome or Sanger sequencing was performed in individuals with a clinical diagnosis of DOORS syndrome without TBC1D24 variants. RESULTS: We identified the same truncating variant in ATP6V1B2 (NM_001693.4:c.1516C>T; p.Arg506*) in nine individuals from eight unrelated families with DOORS syndrome. This variant was already reported in individuals with dominant deafness onychodystrophy (DDOD) syndrome. Deafness was present in all individuals, along with onychodystrophy and abnormal fingers and/or toes. All families but one had developmental delay or intellectual disability and five individuals had epilepsy. We also describe two additional families with DDOD syndrome in whom the same variant was found. CONCLUSION: We expand the phenotype associated with ATP6V1B2 and propose another causal gene for DOORS syndrome. This finding suggests that DDOD and DOORS syndromes might lie on a spectrum of clinically and molecularly related conditions.

A novel NAA10 p.(R83H) variant with impaired acetyltransferase activity identified in two boys with ID and microcephaly.

BACKGROUND: N-terminal acetylation is a common protein modification in human cells and is catalysed by N-terminal acetyltransferases (NATs), mostly cotranslationally. The NAA10-NAA15 (NatA) protein complex is the major NAT, responsible for acetylating ~ 40% of human proteins. Recently, NAA10 germline variants were found in patients with the X-linked lethal Ogden syndrome, and in other familial or de novo cases with variable degrees of developmental delay, intellectual disability (ID) and cardiac anomalies. METHODS: Here we report a novel NAA10 (NM_003491.3) c.248G > A, p.(R83H) missense variant in NAA10 which was detected by whole exome sequencing in two unrelated boys with intellectual disability, developmental delay, ADHD like behaviour, very limited speech and cardiac abnormalities. We employ in vitro acetylation assays to functionally test the impact of this variant on NAA10 enzyme activity. RESULTS: Functional characterization of NAA10-R83H by in vitro acetylation assays revealed a reduced enzymatic activity of monomeric NAA10-R83H. This variant is modelled to have an altered charge density in the acetyl-coenzyme A (Ac-CoA) binding region of NAA10. CONCLUSIONS: We show that NAA10-R83H has a reduced monomeric catalytic activity, likely due to impaired enzyme-Ac-CoA binding. Our data support a model where reduced NAA10 and/or NatA activity cause the phenotypes observed in the two patients.

[Glomuvenous malformations].

In this review, the importance of correct diagnosis of glomuvenous malformations (GVM) is emphasised, and different treatment modalities are discussed. GVM are simple venous malformations located in the skin and subcutis, and GVM has a characteristic blue to reddish cobblestone-like appearance with not fully compressible elements, which can be associated with pain on palpation. Clinically, GVM differ from blue rubber bleb naevus syndrome and common/familial cutaneo-mucosal venous malforma-tions in appearance, compressibility and in having a normal D-dimer concentration.

[Glomuvenous malformations can be very painful and cause diagnostic challenges].

This case report describes three different cases of glomuvenous malformations, which is a rare, autosomal dominant inherited cutaneous venous disease. There is a broad variation in the clinical appearance of these lesions, from flat blue elements to raised purple element with cobblestone appearance. One of the patients in this report experienced intense pain in her lesions, but after surgical resection the pain resolved. All diagnoses were confirmed with biopsy. If in doubt of the diagnosis, biopsy of vascular lesions is important.

Is MED13L-related intellectual disability a recognizable syndrome?

INTRODUCTION: MED13L-related intellectual disability is characterized by moderate intellectual disability (ID), speech impairment, and dysmorphic facial features. We present 8 patients with MED13L-related intellectual disability and review the literature for phenotypical and genetic aspects of previously described patients. MATERIALS AND METHODS: In the search for genetic aberrations in individuals with ID, two of the patients were identified by chromosomal microarray analysis, and five by exome sequencing. One of the individuals, suspected of MED13L-related intellectual disability, based on clinical features, was identified by Sanger sequencing. RESULTS: All 8 individuals had de novo MED13L aberrations, including two intragenic microdeletions, two frameshift, three nonsense variants, and one missense variant. Phenotypically, they all had intellectual disability, speech and motor delay, and features of the mouth (open mouth appearance, macroglossia, and/or macrostomia). Two individuals were diagnosed with autism, and one had autistic features. One had complex congenital heart defect, and one had persistent foramen ovale. The literature was reviewed with respect to clinical and dysmorphic features, and genetic aberrations. CONCLUSIONS: Even if most clinical features of MED13L-related intellectual disability are rather non-specific, the syndrome may be suspected in some individuals based on the association of developmental delay, speech impairment, bulbous nasal tip, and macroglossia, macrostomia, or open mouth appearance.

Comorbidity among HHT patients and their controls in a 20 years follow-up period.

BACKGROUND: Hereditary Haemorrhagic Telangiectasia (HHT) is an autosomal dominant genetic disorder with a wide variety of clinical manifestations due to the presence of multiple arteriovenous malformations in various tissues and organs. OBJECTIVE: To study the need for hospital admittance in a group of HHT patients and matched controls during a 20 years follow-up period commencing in 1995. METHODS: All HHT patients in the County of Funen, Denmark, were included. For each patient, three age and sex matched controls were identified at the time of enrolment. Data on all hospitalisations were extracted from the national health registers and compared with clinical records. The hospitalisations were grouped as HHT relevant or not HHT relevant based on the discharge diagnosis (International Classification of Diseases, ICD10) and with particular focus on infections, bleedings and thromboembolic events. Patients with HHT were compared with controls concerning the first time incidence of each discharge diagnosis. RESULTS: We included 73 HHT patients and 219 controls of which one control was lost to follow-up. HHT-patients had significantly more hospitalisations per person caused by infections in joints and bones, but not caused by infections in general. Bleeding episodes were, as expected, more frequent among the HHT-patients. The study revealed a similar incidence of abscesses and thromboembolisms, including in the central nervous system, among the HHT patients and controls. CONCLUSIONS: Based on this study Danish HHT patients had an increased comorbidity of infections in joints and bones and of bleeding episodes. However, the incidence of thromboembolisms, cerebral abscesses and other conditions commonly considered related to HHT was comparable between the patients and the controls. The patients included in this study were closely monitored at a highly specialised HHT Centre where they received relevant diagnostic evaluation, treatment and counselling. Since this is assumed to benefit the overall health of the patients, it may explain why these patients were less prone to comorbidity than other studies have suggested.

Familial cerebral abscesses caused by hereditary hemorrhagic telangiectasia.

In case of a cerebral abscess without known cause, Pulmonary arteriovenous malformations (PAVM) screening should be performed. If PAVM(s) is identified, Hereditary hemorrhagic telangiectasia (HHT) is very likely and should always be considered. This case shows the benefit of familial screening for HHT and PAVM.

20-year follow-up study of Danish HHT patients-survival and causes of death.

BACKGROUND: Hereditary Haemorrhagic Telangiectasia (HHT) is a dominantly inheritable disorder, with a wide variety of clinical manifestations due to presence of multiple arteriovenous manifestations. The most common mutations are found in HHT1 (ENG) and HHT2 (ACVRL1) patients, causing alterations in the TGF-ß pathway which is responsible for angiogenesis. Modulations of angiogenesis may influence cancer rates. The objective of the study was to evaluate 20-year survival according to HHT subtype, as well as to evaluate differences in causes of death comparing HHT patients and controls. We also wanted to investigate whether cancer morbidity among HHT patients differs from that among controls. RESULTS: We included all HHT patients in the County of Fyn, Denmark, prevalent as of January 1st 1995 in total 73 HHT patients. In addition three age- and sex- matched controls per HHT patient were evaluated, in total 218 controls (one was lost due to registration failure). The controls were defined at start of follow-up in 1995. Information on lifestyle factors was not available. A total of 32 (44%) HHT patients and 97 (44%) controls passed away during follow-up. The survival curves were evenly distributed showing similar survival rates in the two groups. Cancer diagnoses had been registered in the follow-up period in 4 (5%) HHT patients and in 38 (17%) controls. CONCLUSION: The mortality was not increased among Danish HHT patients compared to controls. This study is based on a clinical unselected series of HHT patients with the whole spectrum of severity, independent of need for medical care. Our data also suggest that HHT patients to a lesser degree than the background population are affected by cancer.

[Juvenile polyposis syndrome is a rare cause of gastrointestinal cancer].

Juvenile polyposis syndrome is an autosomal dominant polyposis syndrome. It is characterized by predisposition to multiple juvenile polyps in the gastrointestinal tract and is associated with an increased risk of colorectal and ventricular cancer. Patients and at risk family members should be offered surveillance. This article discusses clinical features and surveillance based on the current literature.

[Juvenile polyposis syndrome and hereditary haemorrhagic telangiectasia syndrome in a patient a with SMAD4 mutation].

Germ line mutations in SMAD4 can cause both juvenile polyposis syndrome and hereditary haemorrhagic telangiectasia syndrome. In this case we present a 37-year-old man with a frameshift mutation in SMAD4. The patient had multiple polyps in the gastrointestinal tract and was diagnosed with colon cancer at the age of 21 and gastro-oesophageal junction cancer at the age of 37. Furthermore the patient had telangiectasias and recurrent epistaxis.

[Juvenile polyposis syndrome is a rare cause of gastrointestinal cancer]. / Juvenil polypose-syndrom er en sjælden årsag til kræft i gastrointestinalkanalen.

Juvenile polyposis syndrome is an autosomal dominant polyposis syndrome. It is characterized by predisposition to multiple juvenile polyps in the gastrointestinal tract and is associated with an increased risk of colorectal and ventricular cancer. Patients and at risk family members should be offered surveillance. This article discusses clinical features and surveillance based on the current literature.