Genomic autopsy to identify underlying causes of pregnancy loss and perinatal death.

Pregnancy loss and perinatal death are devastating events for families. We assessed 'genomic autopsy' as an adjunct to standard autopsy for 200 families who had experienced fetal or newborn death, providing a definitive or candidate genetic diagnosis in 105 families. Our cohort provides evidence of severe atypical in utero presentations of known genetic disorders and identifies novel phenotypes and disease genes. Inheritance of 42% of definitive diagnoses were either autosomal recessive (30.8%), X-linked recessive (3.8%) or autosomal dominant (excluding de novos, 7.7%), with risk of recurrence in future pregnancies. We report that at least ten families (5%) used their diagnosis for preimplantation (5) or prenatal diagnosis (5) of 12 pregnancies. We emphasize the clinical importance of genomic investigations of pregnancy loss and perinatal death, with short turnaround times for diagnostic reporting and followed by systematic research follow-up investigations. This approach has the potential to enable accurate counseling for future pregnancies.

Pathogenic variants in MDFIC cause recessive central conducting lymphatic anomaly with lymphedema.

Central conducting lymphatic anomaly (CCLA), characterized by the dysfunction of core collecting lymphatic vessels including the thoracic duct and cisterna chyli, and presenting as chylothorax, pleural effusions, chylous ascites, and lymphedema, is a severe disorder often resulting in fetal or perinatal demise. Although pathogenic variants in RAS/mitogen activated protein kinase (MAPK) signaling pathway components have been documented in some patients with CCLA, the genetic etiology of the disorder remains uncharacterized in most cases. Here, we identified biallelic pathogenic variants in MDFIC, encoding the MyoD family inhibitor domain containing protein, in seven individuals with CCLA from six independent families. Clinical manifestations of affected fetuses and children included nonimmune hydrops fetalis (NIHF), pleural and pericardial effusions, and lymphedema. Generation of a mouse model of human MDFIC truncation variants revealed that homozygous mutant mice died perinatally exhibiting chylothorax. The lymphatic vasculature of homozygous Mdfic mutant mice was profoundly mispatterned and exhibited major defects in lymphatic vessel valve development. Mechanistically, we determined that MDFIC controls collective cell migration, an important early event during the formation of lymphatic vessel valves, by regulating integrin ß1 activation and the interaction between lymphatic endothelial cells and their surrounding extracellular matrix. Our work identifies MDFIC variants underlying human lymphatic disease and reveals a crucial, previously unrecognized role for MDFIC in the lymphatic vasculature. Ultimately, understanding the genetic and mechanistic basis of CCLA will facilitate the development and implementation of new therapeutic approaches to effectively treat this complex disease.

Subcutaneous nodules following vaccination.

Five patients presented to surgical clinics at our institution with subcutaneous nodules of the upper arm or thigh present for 6-18 months. Excisional or fine-needle biopsy was performed due to diagnostic uncertainty and parental concern. Histopathological examination revealed these to be cutaneous lymphoid hyperplasia in reaction to vaccine components. Nodular reactions with this histopathological pattern are well recognised within vaccine-related literature, but less commonly recognised in patients presenting to general paediatric or surgical clinics. This article reviews literature on delayed-onset nodule formation after vaccination and recommends observation and reassurance as mainstays of management of this largely benign entity.

Dispensing of clomiphene citrate to treat infertility: medication supplied and population prevalence of assisted pregnancies and multiple births.

OBJECTIVE: To determine the proportion of pregnancies resulting in birth that were conceived with the use of clomiphene citrate (CC) and the frequency of multiple pregnancy. DESIGN: Whole-of-population cohort study, constructed through data linkage. Comprehensive Australian Government records of dispensed medications were linked to state Perinatal Registry records for all births of at least 20 weeks' gestation. SETTING: The state of South Australia. PATIENT(S): Women who maintained pregnancy for at least 20 weeks and gave birth between July 2003 and December 2015, a total of 150,713 women with 241,561 pregnancies. INTERVENTION(S): Not applicable. MAIN OUTCOME MEASURE(S): Ongoing pregnancy occurring in proximity to CC, defined as dispensing from 90 days before to the end of a conception window derived from newborn date of birth and gestational age. RESULT(S): Linkage to dispensed prescription records was achieved for 97.9% of women. Women who conceived with CC tended to be older and socioeconomically advantaged and more likely than other women to have a history of miscarriage. Ongoing pregnancies associated with CC comprised 1.6% of the total; 5.7% were multiple births (mostly twins, 94.6%) compared with 1.5% in the remainder (98.5% twins). CONCLUSION(S): In South Australia, 1.6% of pregnancies (1 in 60) of at least 20 weeks' gestation were conceived proximal to CC dispensing. Of these, 5.7% were multiple pregnancies. This takes the proportion of women who achieved an ongoing pregnancy with medical assistance from 4.4%, based on reports from assisted reproductive technology clinics, to 6% in total.

Paternal mosaicism for a novel PBX1 mutation associated with recurrent perinatal death: Phenotypic expansion of the PBX1-related syndrome.

Autosomal dominant (de novo) mutations in PBX1 are known to cause congenital abnormalities of the kidney and urinary tract (CAKUT), with or without extra-renal abnormalities. Using trio exome sequencing, we identified a PBX1 p.(Arg107Trp) mutation in a deceased one-day-old neonate presenting with CAKUT, asplenia, and severe bilateral diaphragmatic thinning and eventration. Further investigation by droplet digital PCR revealed that the mutation had occurred post-zygotically in the father, with different variant allele frequencies of the mosaic PBX1 mutation in blood (10%) and sperm (20%). Interestingly, the father had subclinical hydronephrosis in childhood. With an expected recurrence risk of one in five, chorionic villus sampling and prenatal diagnosis for the PBX1 mutation identified recurrence in a subsequent pregnancy. The family opted to continue the pregnancy and the second affected sibling was stillborn at 35 weeks, presenting with similar severe bilateral diaphragmatic eventration, microsplenia, and complete sex reversal (46, XY female). This study highlights the importance of follow-up studies for presumed de novo and low-level mosaic variants and broadens the phenotypic spectrum of developmental abnormalities caused by PBX1 mutations.

Pseudodiastrophic dysplasia expands the known phenotypic spectrum of defects in proteoglycan biosynthesis.

BACKGROUND: Pseudodiastrophic dysplasia (PDD) is a severe skeletal dysplasia associated with prenatal manifestation and early lethality. Clinically, PDD is classified as a 'dysplasia with multiple joint dislocations'; however, the molecular aetiology of the disorder is currently unknown. METHODS: Whole exome sequencing (WES) was performed on three patients from two unrelated families, clinically diagnosed with PDD, in order to identify the underlying genetic cause. The functional effects of the identified variants were characterised using primary cells and human cell-based overexpression assays. RESULTS: WES resulted in the identification of biallelic variants in the established skeletal dysplasia genes, B3GAT3 (family 1) and CANT1 (family 2). Mutations in these genes have previously been reported to cause 'multiple joint dislocations, short stature, and craniofacial dysmorphism with or without congenital heart defects' ('JDSCD'; B3GAT3) and Desbuquois dysplasia 1 (CANT1), disorders in the same nosological group as PDD. Follow-up of the B3GAT3 variants demonstrated significantly reduced B3GAT3/GlcAT-I expression. Downstream in vitro functional analysis revealed abolished biosynthesis of glycosaminoglycan side chains on proteoglycans. Functional evaluation of the CANT1 variant showed impaired nucleotidase activity, which results in inhibition of glycosaminoglycan synthesis through accumulation of uridine diphosphate. CONCLUSION: For the families described in this study, the PDD phenotype was caused by mutations in the known skeletal dysplasia genes B3GAT3 and CANT1, demonstrating the advantage of genomic analyses in delineating the molecular diagnosis of skeletal dysplasias. This finding expands the phenotypic spectrum of B3GAT3-related and CANT1-related skeletal dysplasias to include PDD and highlights the significant phenotypic overlap of conditions within the proteoglycan biosynthesis pathway.

Paediatric acute lymphoblastic leukaemia causing acute leukaemic occlusion of the proximal middle cerebral artery: Treatment with endovascular thrombectomy.

Optimal treatment for ischaemic stroke in paediatric acute lymphoblastic leukaemia (ALL) is unclear. We describe an ischaemic stroke in an adolescent with ALL who underwent successful endovascular thrombectomy following leukaemic arterial occlusion. Endovascular thrombectomy should be considered in paediatric ALL patients with acute ischaemic stroke and large vessel occlusion.

Familial GATA6 mutation causing variably expressed diabetes mellitus and cardiac and renal abnormalities.

A 26-year-old man presented with a combination of permanent neonatal diabetes due to pancreatic aplasia, complex congenital heart disease, central hypogonadism and growth hormone deficiency, structural renal abnormalities with proteinuria, umbilical hernia, neurocognitive impairment and dysmorphic features. His older brother had diabetes mellitus due to pancreatic hypoplasia, complex congenital heart disease, hypospadias and umbilical hernia. Their father had an atrial septal defect, umbilical hernia and diabetes mellitus diagnosed incidentally in adulthood on employment screening. The proband's paternal grandmother had a congenital heart defect. Genetic testing of the proband revealed a novel heterozygous missense variant (Chr18:g.19761441T>C, c.1330T>C, p.Cys444Arg) in exon 4 of GATA6, which is class 5 (pathogenic) using American College of Medical Genetics and Genomics guidelines and is likely to account for his multisystem disorder. The same variant was detected in his brother and father, but not his paternal grandmother. This novel variant of GATA6 likely occurred de novo in the father with autosomal dominant inheritance in the proband and his brother. The case is exceptional as very few families with monogenic diabetes due to GATA6 mutations have been reported to date and we describe a new link between GATA6 and renal pathology. Learning points: Monogenic diabetes should be suspected in patients presenting with syndromic features, multisystem congenital disease, neonatal-onset diabetes and/or a suggestive family history. Recognition and identification of genetic diabetes may improve patient understanding and empowerment and allow for better tailored management. Identification of a genetic disorder may have important implications for family planning.

Retrospective analysis of South Australian pediatric oral and maxillofacial pathology over a 16-year period.

AIM: The epidemiological features and distribution of pediatric oral and maxillofacial pathology in South Australia, Australia, is unknown. The medical and dental specialties involved in the management of oral and maxillofacial pathology is also unknown. The aim of the present study was to audit oral and maxillofacial pathology specimens submitted for diagnosis in a pediatric tertiary-referral hospital setting. METHODS: Histopathology records were retrieved from the Women's and Children's Hospital, Adelaide over a 16-year period. Age, sex, histopathological diagnosis, location of the lesion, and department involved were recorded. Lesions were classified into 12 categories. RESULTS: A total of 676 lesions involving the oral and maxillofacial region were collected from patients aged 0-18 years. The mean age was 8.71 years. Diagnosis was not significantly associated with sex (P = 0.123). A total of 97.37% of cases were benign, with connective tissue and salivary gland lesions most frequently biopsied and more frequently biopsied by medical departments. Mucoceles (19.23%) were most commonly diagnosed, followed by dentigerous cysts (5.62%). The Department of Paediatric Dentistry submitted most specimens, followed by the Department of Otolaryngology, the Australian Craniofacial Unit, and the Departments of Paediatric Surgery and Plastics. CONCLUSION: The present study provides valuable understanding into the epidemiological features of, and the specialties involved in, oral and maxillofacial histopathology in an Australian pediatric population.

Histological analysis of 41 dentigerous cysts in a paediatric population.

BACKGROUND: Dentigerous cysts are usually of developmental nature but may be of inflammatory origin especially in paediatric populations. It is important to understand the histological features of dentigerous cysts to enable accurate diagnosis. The aim of this study is to present epidemiological, clinical features and histopathological features of dentigerous cysts seen in a paediatric tertiary referral hospital. METHOD: The medical, radiographic and histopathology records of the Department of Pathology, Women's and Children's Hospital, Adelaide, Australia, during January 1998 to December 2013 were reviewed for patients with dentigerous cysts. All cases were re-examined by a specialist oral pathologist, consultant paediatric pathologist and paediatric dentistry registrar. RESULTS: Forty-one cases of dentigerous cysts were found. Patients in the permanent dentition were most frequently affected. Male predilection was observed (male:female 2.42:1). The posterior mandible was the most frequently affected region (63.42%) although maxillary canines were the teeth most commonly associated with dentigerous cysts (29.27%). The majority of cases were incidental findings. Squamous epithelium showing pseudoepitheliomatous hyperplasia (46%) was frequently observed and was significantly present with thicker epithelium (P < 0.0001) and an acute and chronic inflammatory infiltrate (P < 0.001). Inflammatory infiltrate was seen in 75.6% of cases. CONCLUSIONS: The current study provides increased knowledge of the histological features of dentigerous cysts in a large retrospective series of paediatric patients and provides further evidence regarding the frequency of inflammatory dentigerous cysts.

Development of the Human Fetal Kidney from Mid to Late Gestation in Male and Female Infants.

BACKGROUND: During normal human kidney development, nephrogenesis (the formation of nephrons) is complete by term birth, with the majority of nephrons formed late in gestation. The aim of this study was to morphologically examine nephrogenesis in fetal human kidneys from 20 to 41weeks of gestation. METHODS: Kidney samples were obtained at autopsy from 71 infants that died acutely in utero or within 24h after birth. Using image analysis, nephrogenic zone width, the number of glomerular generations, renal corpuscle cross-sectional area and the cellular composition of glomeruli were examined. Kidneys from female and male infants were analysed separately. FINDINGS: The number of glomerular generations formed within the fetal kidneys was directly proportional to gestational age, body weight and kidney weight, with variability between individuals in the ultimate number of generations (8 to 12) and in the timing of the cessation of nephrogenesis (still ongoing at 37weeks gestation in one infant). There was a slight but significant (r2=0.30, P=0.001) increase in renal corpuscle cross-sectional area from mid gestation to term in females, but this was not evident in males. The proportions of podocytes, endothelial and non-epithelial cells within mature glomeruli were stable throughout gestation. INTERPRETATION: These findings highlight spatial and temporal variability in nephrogenesis in the developing human kidney, whereas the relative cellular composition of glomeruli does not appear to be influenced by gestational age.

Impact of preterm birth on the developing myocardium of the neonate.

BackgroundGlobally, ∼10% of infants are born before full term. Preterm birth exposes the heart to the demands of postnatal cardiovascular function before cardiac development is complete. Our aim was to examine, in hearts collected from infants at autopsy, the effects of preterm birth on myocardial structure and on cardiomyocyte development.Methods and resultsHeart tissue was collected at perinatal autopsies of 16 infants who died following preterm birth between 23 and 36 weeks of gestation, and survived for 1-42 days; the hearts of 37 appropriately grown stillborn infants, aged 20-40 weeks of gestation, were used for comparison. Using confocal microscopy and image analysis, cardiomyocyte proliferation, maturation, ploidy, and size were quantified, and interstitial collagen and myocardial capillarization were measured. Preterm birth resulted in a marked reduction in the proliferation of cardiomyocytes relative to age-matched stillborn infant controls (preterm vs. control P<0.0001). In contrast, preterm birth did not affect heart weight, capillarization, interstitial collagen or cardiomyocyte maturation, ploidy, and size.ConclusionsPreterm birth appears to lead to an abrupt reduction in cardiomyocyte cell division. This reduced cardiomyocyte proliferation in preterm infants may adversely impact upon the final number of cardiomyocytes which may reduce cardiac functional reserve, and impair the reparative capacity of the myocardium.

Intrauterine Fetal Death With Vanishing Gastroschisis and Post Mortem Examination Findings.

We present a severe case of vanishing gastroschisis resulting in intrauterine death with post mortem examination findings. Gastroschisis is defined as a full thickness paraumbilical abdominal wall defect associated with evisceration of fetal intestine. It is almost always right-sided. Vanishing gastroschisis is an extremely rare form of gastroschisis that results in short bowel syndrome due to exteriorized bowel disconnected from the lumen of the rest of the bowel proximally as well as distally in association with partial or complete closure of the abdominal wall. This case is only the second published case of vanishing gastroschisis resulting in intrauterine fetal death including post mortem examination findings. It highlights the importance of being aware of this rare form of gastroschisis and provides insights regarding pathogenesis, ultrasound surveillance, and antenatal counseling.

Pemphigus Vulgaris and Eosinophilic Esophagitis in a 13-Year-Old Boy: Case Report and Review of the Literature.

This case report presents a 13-year-old boy referred to the Department of Paediatric Dentistry, Women's and Children's Hospital, Adelaide, South Australia, Australia, with a 5-week history of severe oral ulcerations and significant weight loss of unknown origin. The diagnosis of pemphigus vulgaris was made after histologic and immunofluorescent examination of an intraoral deep incisional biopsy, with eosinophilic esophagitis also diagnosed during the initial upper gastrointestinal endoscopy. The association between pemphigus vulgaris and eosinophilic esophagitis in this case, although previously unreported, is explicable on the basis of dysregulation of desmoglein 1 (DSG1). This case report identifies a new clinical association that could help clinicians identify further such cases and provides insight into the pathogenesis of both conditions.

Occult Adrenocortical Carcinoma and Unexpected Early Childhood Death.

A four-year-old previously well boy collapsed unexpectedly and was taken immediately to hospital, where he developed seizures and cardiogenic shock with lethal, rapidly progressing multi-organ failure. At autopsy, the height was >90th percentile and there were indications of early virilization. Internally, a friable tumor of the left adrenal gland was identified that had invaded the left renal vein and inferior vena cava. Histology revealed typical features of an adrenocortical carcinoma with aggregated trabeculae of cells containing abundant eosinophilic cytoplasm and large pleomorphic nuclei. There was strong positive cytoplasmic staining for inhibin; mitochondria were shown on electron microscopy to contain prominent electron-dense granules. Death was due to massive pulmonary tumor embolism. Although adrenocortical carcinomas are very rare and are more commonly found in adults, the current case demonstrates that they may also occur in childhood and be responsible for unexpected death by the very unusual mechanism of tumor embolism.

Recurrent chronic histiocytic intervillositis with intrauterine growth restriction, osteopenia, and fractures.

Chronic histiocytic intervillositis (CHI) is characterized by the presence of histiocytes within the intervillous space of the placenta. The pathogenesis is unclear but available evidence supports an alloimmune mechanism on the basis of the presence in maternal blood of HLA antibodies directed against paternal HLA antigens. CHI has a high risk of recurrence and of abnormal perinatal outcomes. Little is known about the effects of CHI on the developing fetus, in particular on the growth and development of the skeleton. We have studied a woman whose third pregnancy was terminated after ultrasonography showed severe intrauterine growth restriction, raising the possibility of a lethal skeletal dysplasia. Postmortem radiographs showed multiple fractures and other signs of osteogenesis imperfecta (OI). However, bone histology was not typical of OI and no abnormalities were identified by sequencing OI genes. The subsequent pregnancy was also severely growth restricted and was terminated. The placenta showed chronic histiocytic intervillositis, which, on retrospective review, had also been present in her second and third pregnancies. Her fifth pregnancy was again associated with intrauterine growth restriction and CHI but resulted in a premature birth. CHI can be associated with radiographic features that mimic OI and should be considered when fetal fractures occur in the context of recurrent miscarriage, fetal death in utero, and intrauterine growth restriction. The correct diagnosis can be made by histopathology of the placenta, supported by bone histology and normal results of molecular studies for OI. © 2016 Wiley Periodicals, Inc.

Renal tubular epithelial vacuoles-a marker for both hyperlipidemia and ketoacidosis at autopsy.

Review of 15 cases of nephrotic syndrome found that eight had significant hyperlipidemia with serum cholesterol levels ranging between 10.59 and 18.60 mmol/L (mean 12.88) and serum triglyceride levels between 2.30 and 9.92 mmol/L (mean 4.58); all of these cases displayed basal lipid vacuolization. Seven of the 15 study cases had normal-mild hyperlipidemia with serum cholesterol levels ranging between 4.71 and 7.54 mmol/L (mean 6.02) and serum triglyceride levels between 0.65 and 4.1 mmol/L (mean 1.57). Six of the seven cases had basal lipid vacuoles (86%). Of these, five cases were hyperlipidemic and one case had borderline hyperlipidemia with a serum cholesterol level of 4.71 mmol/L. Although hyperlipidemia was associated with renal tubular epithelial vacuolization, the vacuoles appeared morphologically different to those found in ketoacidosis. This study has shown that while hyperlipidemia in isolation may result in basal lipid vacuolization within renal tubular epithelial cells, the phenotype differs from that observed in ketoacidosis.