Prenatal Diagnosis In Subsequent Pregnancies Research Articles

Novel compound heterozygous mutations in the PLEC gene in a neonate with epidermolysis bullosa simplex with pyloric atresia.

Epidermolysis bullosa (EB) is a heterogeneous group of inherited disorders characterized by the blistering of the skin and mucous membranes. Although the molecular basis of EB has been significantly elucidated, the precise phenotypes of the lethal types of EB have not been completely characterized. Herein, we report a severe case of EB with pyloric atresia (PA). The patient was a Japanese boy who not only had skin lesions but also various complications such as PA, dysphagia, hypotonia, infectious keratitis with corneal ulcer, obstructive uropathy and protein-losing enteropathy. Genetic analysis led to the identification of two novel compound heterozygous mutations in the last exon of the plectin (PLEC) gene. Based on this finding, EB simplex with PA was diagnosed. Immunostaining with anti-plectin antibodies revealed truncated plectin proteins lacking the C-terminus in the patient's skin. We also conducted a prenatal diagnosis in subsequent pregnancy. Our report further highlights the crucial role of plectin in many organs and provides valuable information regarding the phenotypes resulting from mutations in the PLEC gene.

Newborn Screening for Sickle Cell Disease Among Tribal Populations in the States of Gujarat and Madhya Pradesh in India: Evaluation and Outcome Over 6 Years.

Sickle cell disease (SCD) poses considerable public health problems in India. This study was undertaken to understand the clinical course of SCD among children identified during newborn screening programmes in Gujarat and Madhya Pradesh where the frequency of the HbS gene is high. A total of 8,916 newborn babies 8,411 from Gujarat and 505 from Madhya Pradesh were screened over 6 years (2010–2016) using HPLC and the diagnosis was confirmed by molecular analysis in a subset. A total of 128 babies (122 Gujarat, 6 Madhya Pradesh) were identified with sickle cell disease, of whom 87 (69 HbSS, 18 HbS-β thalassemia) from Gujarat were followed for 0.5–6.6 years. Acute painful events, severe anemia and fever with infections were the major complications and 23 babies required hospitalization. Severe to moderate clinical presentation was found in 13.8% babies with SCD whereas, 86.2% babies had a milder presentation. Presence of ameliorating factors (α-thalassemia and Xmn 1 polymorphism) did not have a discernible effect on the clinical severity. Parents of babies with SCD were educated and counseled for home care. Distribution of mobile phones to 44 families having babies with SCD was beneficial as it allowed regular contact with patients and their families. Genetic counseling to the affected families has increased the awareness and acceptance for prenatal diagnosis and 18 couples opted for prenatal diagnosis in subsequent pregnancies. SCD is not always mild among tribal groups in India. Therefore, facilities for early diagnosis and prophylactic treatment in the tertiary care centers should be made available. The difficulties in regular follow up of the babies in remote rural areas have also been highlighted.

Atypical Mongolian Spots in an Infant

Background: Atypical Mongolian spots are lesions that are aberrant in location (over the abdomen, back, legs, shoulders, or arms), extensive in distribution, persist beyond early infancy, and/or progressively increase in number. These are frequently associated with lysosomal storage disorders or neurocristopathies. Clinical Description: A 4-month-old girl presented with a common cold. Extensive aberrant Mongolian spots over the back, buttocks, lower limbs, and new onset grayish-blue macular spots over the abdomen prompted us to do a detailed evaluation to look for any underlying pathology. Other salient clinical findings included coarse facies, hepatomegaly, absence of significant developmental delay, bilateral macular cherry red spots, and ovoid-shaped vertebral bodies. The clinical phenotype was that of a lysosomal storage disorder possibly GM1 gangliosidosis. This was confirmed by deficient levels of ß-galactosidase. Management: The parents underwent genetic counseling. The infant was enrolled in an early intervention program. By the age of 6 months, the infant had not acquired any new developmental skills and new Mongolian spots did not develop. Subsequently, the family was lost to follow-up. Conclusion: Infants with aberrant Mongolian spots need to undergo an in-depth evaluation to identify underlying systemic disorders, even if they are asymptomatic. Diagnosis helps in providing supportive care to the child, specific therapy (if available) and the option of prenatal diagnosis in subsequent pregnancies.

Functional assay for analysis of variants of uncertain significance in maple syrup urine disease

Introduction: Enhanced molecular characterisation using high-throughput sequencing has significantly improved patient diagnosis and management. However, the identification of variants of uncertain significance (VUS) limits its use for clinical decision making, such as prenatal diagnosis in subsequent pregnancies. Case report: We report a female infant who presented with mild gross motor delay at 4 months and developed seizures with hypoglycaemia at 5 months. Plasma amino acid and urine organic acid findings were consistent with Maple syrup urine disease (MSUD), despite a normal newborn screening test for this condition. MSUD results in deficiency of branched-chain alpha-ketoacid dehydrogenase, responsible for leucine, isoleucine, and valine degradation, caused by biallelic pathogenic variants in BCKDHA, BCKDHB, or DBT genes. Results: Molecular analysis in this patient identified two VUS, c.434-15_434-4del and c.365A>G (p. Tyr122Cys) in the DBT gene. Functional testing, in the form of leucine decarboxylation studies in fibroblasts revealed deficient function and mRNA splicing studies provided additional data that permitted variant reclassification and subsequent prenatal testing. Conclusion: This case reinforces the need for specialist biochemical genetic laboratories to retain their ability to perform functional assays to aid the resolution of VUS.

Hereditary tyrosinemia presenting as hepatocellular carcinoma in a young infant

Hereditary tyrosinemia type 1 is an inborn error of metabolism that affects numerous organs, particularly liver, kidneys and peripheral nerves. It usually presents in infants less than six months of age with features of liver failure, hepatoblastoma or hepatocellular carcinoma. Diagnosis is by a combination of clinical, biochemical and imaging features. We report here the case of a four months old infant presenting with massive hepatosplenomegaly and coagulopathy. He was detected to have hepatocellular carcinoma secondary to tyrosinemia and initiated on treatment. This report highlights the importance of considering tyrosinemia in the differential diagnosis of infants presenting with hepatic disease. Early diagnosis is important due to the presence of effective treatment and for prenatal diagnosis in subsequent pregnancies.

Unclassified Sudden Infant Death Due to Congenital Long QT Syndrome with TRPM4 Mutation

Background: Congenital long QT syndrome (cLQTS) are heritable disorders due to genetic mutations causing prolonged corrected QT (QTc) interval that may result in fatal arrhythmias. Clinical Description: A well 20-day-old, exclusively breastfed boy had an episode of unresponsiveness with no other symptoms. There was a history of four previous unexplained infantile deaths after similar complaints. General and systemic examination was normal. The differential diagnoses were neonatal apnea, seizures, and inborn errors of metabolism. Management: Sepsis, hypoglycemia, and electrolyte imbalance were ruled out. Electrocardiography (ECG), chest radiograph, and echocardiograph were normal. Ultrasonogram of the cranium ruled out structural abnormality and bleed. Electroencephalogram was normal. First-line metabolic investigations were normal. On day 28 of life, he had a recurrent episode of apnea. ECG evaluation during this episode revealed a prolonged QTc interval. Suspecting cLQTS, Trio Whole Exome Sequencing for mutations in the cLQTS susceptibility genes was performed in the proband and parents. A heterozygous variation, c.290C>T; p. Thr97Met in TRPM4 was identified in the symptomatic neonate and asymptomatic mother, suggesting autosomal dominant inheritance. The baby was started on oral propranolol, but succumbed at 8 weeks. The mother was referred for cardiac management and parents counseled about possible prenatal diagnosis in subsequent pregnancies. Conclusion: cLQTS should be suspected in neonatal apnea, when no other cause is appreciable. A normal ECG does not exclude cLQTS. If there is a strong suspicion, repeat ECGs and appropriate genetic testing should be done. Patients should be managed according to standard guidelines.

Polyploidy in First and Second Trimester Pregnancies in Romania - a Retrospective Study.

Polyploidy is a rare lethal cytogenetic anomaly in pregnancies, generally leading to pregnancy termination. This study aims to compare first and second trimester polyploidy in pregnancies and describe the underlying mechanisms. A retrospective study was conducted in three medical genetics laboratories, collecting cases from Eastern, Southern, and Western Romania. The period of interest was January 2008 to December 2018. Prenatal samples (chorionic villi and amniotic fluid) and miscarriage samples were tested by standard karyotyping, as well as QF-PCR or FISH as complementary or alternative techniques. In first trimester pregnancies, we report cytogenetic results of chorionic villi samples from miscarriages: 25 triploid cases and 13 tetraploid cases. In second trimester samples obtained by amniocentesis, cytogenetic findings were positive for 17 triploid cases. Maternal age, age of the pregnancy, and fetal gender identified by ultrasound were recorded in all cases and, additionally, data on biochemical risk and ultrasonographic findings for second trimester pregnancies. Cytogenetic investigations of spontaneous abortions provide valuable information on the cause of abortion. This information is crucial for genetic counseling and may also contribute to prenatal diagnosis in subsequent pregnancies.

Exome Sequencing Identifies RET Associated Hirschsprung Disease in a Fetus with Echogenic Bowel

AbstractThis is report of a case of RET associated Hirschsprung disease in a fetus diagnosed using exome sequencing. The fetus initially presented with echogenic bowel at 16 weeks with maternal first trimester serum screen showing increased risk for Trisomy 21. Amniotic fluid karyotype, ΔF508 CFTR genotype and maternal TORCH serology were normal. Subsequent ultrasonograms showed dilated bowel loops, predominantly large bowel. Following delivery at 24 weeks, a post-mortem examination was performed. Dilated bowel was confirmed with no structural gut abnormality and no other dysmorphic finding. Histopathology revealed agangliosis confirming a diagnosis of Hirschsprung disease. Exome sequencing done on fetal DNA from amniotic fluid revealed a putative pathogenic heterozygous c.1438G > A variant in exon 7 of RET gene, which was inherited from the asymptomatic mother. This enabled genetic counseling and prenatal diagnosis in subsequent pregnancy.

Genotyping of five Pakistani patients with severe inherited factor X deficiency: identification of two novel mutations.

: Congenital factor X deficiency is a rare coagulation defect characterized by variable bleeding tendency. The aim of the study was to give a first insight of F10 gene mutations in Pakistani probands. Direct sequencing and/or next-generation sequencing was performed on the coding regions, boundaries and 5' and 3' untranslated regions of the F10 gene in five severe factor X-deficient patients from Pakistan. All patients were born from consanguineous marriages and displayed FX:C levels below 2%. Sequencing revealed five different substitutions, including three previously reported p.Ala15Asp, p.Gly406Ser, and p.Gly420Arg missense variants, and also two novel variants: p.Cys57Arg and p.Gln175*. Though one genotype could not be characterized, we were able to confirm the inherited nature of the defect using familial studies. As the copy number variations were ruled out, we hypothesized the presence of deep intronic mutants that might have escaped detection from sequencing or abnormalities in epigenetic regulation. Three patients presented with severe clinical symptoms, in the early days of life, whereas two presented only with trauma-provoked bleeds and bruises later in life. Those patients with milder forms bore the p.Gly406Ser at the homozygous state and F10 unknown alleles, respectively. F10 mutation spectrum in Pakistan is heterogeneous as seen in other populations. Identification of the F10 mutations is important for genetic counseling and prenatal diagnosis in subsequent pregnancies.

Ethical and counseling challenges in prenatal exome sequencing.

Ethical and counseling challenges are expected with the introduction of prenatal whole exome sequencing. In this study, we describe specific challenges identified through the UNC-Chapel Hill Prenatal Exome Sequencing Study. Participants were a subset of women participating in the fetal exome study, which has enrolled 73 mother-father-fetus trios in pregnancies diagnosed with structural anomalies and normal standard genetic testing results. In this descriptive study, cases were reviewed by members of the research team, including a bioethicist, to identify counseling challenges. Illustrative cases were chosen by group consensus. Four illustrative cases were identified for further analysis. Challenges included need for adequate counseling and informed consent, challenges in prenatal variant interpretation, performing prenatal diagnosis in subsequent pregnancies, inability to identify a genetic etiology, and identifying parental secondary findings. Our study illustrates several challenges identified in an ongoing prenatal exome study. While genomic medicine is a powerful tool for prenatal diagnosis, it is important that clinicians understand the ethical implications and parental perceptions of this testing modality.

Exome sequencing identifies novel ACE splice-site variant in a fetus with renal tubular dysgenesis

We report a 32-week fetus conceived of consanguineous parentage which presented with severe early onset oligohydramnios and history of a similarly affected sibling in previous pregnancy. Ultrasonography and autopsy were inconclusive, prompting exome sequencing on fetal DNA. This resulted in identification of a homozygous novel 3' splice-site variation in intron 17 of the ACE gene (NM_000789.3:c.2642-1G>A), confirming diagnosis of autosomal recessive renal tubular dysgenesis, and facilitating prenatal diagnosis in subsequent pregnancy.

Prenatal diagnosis of cystic fibrosis in combination with herpetic infection in parents with uncompensated family history

Cystic fibrosis (CF) is a chronic genetic disorder that affects the exosecretory glands responsible for the production of mucus and sweat; as well as respiratory, digestive and reproductive systems. The article describes a brief description of this disease, the features of intrauterine manifestations and differential diagnosis with other conditions.In most cases, prenatal diagnosis of CF is offered to a family that already has children with CF. Regarding the prospective prenatal diagnosis of CF in families without CF history, as well as in couples with established status of heterozygous carrier of mutations in the CFTR gene, it is presented mainly in sporadic cases. In all other cases, prenatal diagnosis of CF is based on ultrasound detection of increased intestinal echogenicity. The hyperechogenic intestine is observed in 50–75% fetuses with CF. The incidence of intrauterine infection in fetuses with the hyperechogenic intestine is varies from 0 to 10%. The spectrum of perinatal infections is more often represented by cytomegalovirus, herpes, syphilis, toxoplasmosis, rubella and parvovirus B19.The second trimester amniotic fluid contains two main enzymes (alkaline phosphatase and gamma-glutamyltranspeptidase), whose decline of level is a reliable marker for CF. The article presents a clinical case of prenatal diagnosis of CF in combination with intrauterine infection with herpes simplex virus in 20 weeks pregnancy in a fetus with a hyperechoic intestine. Whenthe amniotic fluid was investigated in a fetus with a normal karyotype are revealed decline of alkaline phosphatase and gamma-glutamyltranspeptidase levels, the mutation delF508 CFTR in the homozygous state and the DNA regions homologous HSV I, II types. Taking into account the unfavorable morbid prognosis, the fetus with CF was eliminated for 22 weeks pregnancy at the family’s request. At autopsy were found the typical manifestations of CF in the female abortus. The molecular gene study of both parents confirmed the heterozygous carrier state. The family received recommendations on the mandatory prenatal diagnosis in subsequent pregnancies.

Goltz-Gorlin Syndrome: Revisiting the Clinical Spectrum

To describe the varying phenotypic spectrum of Focal Dermal Hypoplasia (FDH) and to emphasize the need for identifying the condition in mildly affected females which is crucial for offering a prenatal diagnosis in subsequent pregnancy owing to the risk of having a severely affected baby. The phenotype-genotype correlation of 4 patients with FDH, over a period of 11 y from the genetic clinic in a tertiary care centre from Kerala, India was done. All four mutation proven patients were females (2 adults and 2 children). One of the adult female subjects were mildly affected, though she had a history of having a severely affected female child who expired on day six. Among the 2 affected children, one of them had an unaffected mother and the other had an affected mother. FDH has a wide clinical spectrum from very subtle findings to severe manifestations. The lethality of the condition in males and the disfigurement and multisystem involvement in females highlights the importance of confirmation of diagnosis by molecular analysis so that the family can be offered prenatal diagnosis in subsequent pregnancy.

Fetal Pathology of Neural Tube Defects - An Overview of 68 Cases.

The prevalence of neural tube defects worldwide is 1 - 2 per 1000 neonates. Neural tube defects result from a disturbance of neurulation in the 3rd or 4th week of development and thus represent the earliest manifestation of organ malformation. Neural tube defects (NTD) are classified into cranial dysraphism leading to anencephaly or meningoencephalocele and spinal dysraphism with or without meningomyelocele. In isolated form they have multifactorial causes, and the empirical risk of recurrence in Central Europe is 2%. As associated malformations they tend to occur sporadically, and in monogenic syndromes they follow Mendelian inheritance patterns with a high risk of recurrence. Autopsies were performed on 68 fetuses following a prenatal diagnosis of NTD and induced abortion. The incidence of NTDs in our autopsied fetuses was 8% and 11% in fetuses with malformations. The percentage of fetuses with anencephaly, encephalocele or spina bifida was 24, 18, and 60%*, respectively. Analysis of the sex distribution showed a female preponderance in cranial dysraphisms but the sex distribution of spina bifida cases was equal. The extent and localization of NTDs varied, with lumbosacral cases clearly predominating. The proportion of isolated, associated and syndromic neural tube defects was 56, 23.5 and 20.6% respectively. In the majority of syndromes, the neural tube defect represented a not previously observed syndromic feature. The high proportion of NTDs with monogenic background underlines the importance of a syndrome oriented fetal pathology. At the very least it requires a thourough photographic and radiographic documentation of the fetal phenotype to enable the genetic counsellor to identify a syndromic disorder. This is necessary to determine the risk of recurrence, arrange confirming mutation analyses and offer targeted prenatal diagnosis in subsequent pregnancies.

Complex Cardiac Defect in a Fetus with Trisomy 18: A Case Report

AbstractThis is a case report of a foetus which was brought for postmortem evaluation following antenatal detection of a complex cardiac defect. Presence of dysmorphism and other malformations like gut malrotation, bladder outlet obstruction, and esophageal stenosis led to suspicion of a syndromic diagnosis. Fetal karyotyping confirmed a diagnosis of Trisomy 18 (Edwards syndrome). This facilitated appropriate genetic counseling of the family and guidance for prenatal diagnosis in subsequent pregnancies.

PCR in the Analysis of Clinical Samples: Prenatal and Postnatal Diagnosis of Inborn Errors of Metabolism.

Inborn errors of metabolism (IEMs) are individually rare but collectively common. As more and more genes are cloned and specific disease-causing mutations are identified, the diagnosis of IEMs is becoming increasingly confirmed by mutation analysis. Diagnosis is important not only for treatment and prognosis but also for genetic counselling and prenatal diagnosis in subsequent pregnancies. A wide range of molecular methods is available for the identification of mutations and other DNA variants, most of which are based on the Polymerase Chain Reaction (PCR). In this chapter, we focus on PCR-based methods for the detection of point mutations or small deletions/insertions as these are the most frequent causes of IEMs.

Prenatal Diagnosis of Idiopathic Infantile Arterial Calcification

AbstractIdiopathic infantile arterial calcification is a rare disorder which is generally fatal and characterized by extensive calcification of large- and medium-sized arteries. The diagnosis is usually made at autopsy or in the neonatal period, when there is cardiac failure. Prenatal diagnosis is possible in the latter half of pregnancy when there are hyperechoic vessel walls, hypertrophied ventricular musculature, and nonimmune fetal hydrops. There are only few cases reported to have been diagnosed antenatally. The inheritance is autosomal recessive and most of the affected individuals have mutations in ENPP1 and ABCC6 genes. Molecular genetic tests and genetic counseling should be offered to provide early prenatal diagnosis in subsequent pregnancies.

Cytogenetic findings in patients with intellectual disability and/or multiple congenital anomalies

Introduction: Chromosomal abnormalities are a major etiology of intellectual disability (ID) and multiple congenital anomalies (MCAs). Screening for chromosomal aberrations by clinical diagnostic techniques has been primarily performed through standard karyotyping. Methods: A cytogenetic study involving 1730 individuals with ID and/or MCA was conducted using lymphocyte culture and high-resolution G-banding method. Results: Various types of chromosomal abnormalities were detected in 440 patients (25.5%). Numerical and structural chromosomal abnormalities, respectively, were observed in 63.3% (278 out of 440) and 36.7% (162 out of 440) patients. Among the chromosomal abnormalities, sexual chromosomal abnormalities were found in some cases, and Klinefelter syndrome with 2.5% frequency was the most frequent sex chromosomal abnormality. Autosomal abnormalities were found in cases, and Down syndrome was the most frequent autosomal chromosomal abnormality occurring in 41.0% of detected abnormalities. Conclusion: The higher contribution of chromosome aberrations in the northwest of Iran indicates the importance of cytogenetic evaluation in the etiology of MCA and/or ID patients. Genetic counseling was provided to the family members to explain the recurrence risk as well as the need for prenatal diagnosis in subsequent pregnancies and management of patients by collected data bank.

Novel ABCA12 mutations in harlequin ichthyosis: A journey from photo diagnosis to prenatal diagnosis

Harequin ichthyosis is a severe autosomal recessive ichthyosis of congenital onset caused by biallelic mutations in the ABCA12 gene. We report two neonates of Indian origin with harlequin ichthyosis. The parents were retrospectively found to have novel mutations in ABCA12 gene after neonatal demise, which helped in providing prenatal diagnosis in subsequent pregnancies.

Clinical and hematological presentation among Indian patients with common hemoglobin variants

BackgroundCo-inheritance of structural hemoglobin variants like HbS, HbDPunjab and HbE can lead to a variable clinical presentation and only few cases have been described so far in the Indian population. MethodsWe present the varied clinical and hematological presentation of 22 cases (HbSDPunjab disease-15, HbSE disease-4, HbDPunjabE disease-3) referred to us for diagnosis. ResultsTwo of the 15 HbSDPunjab disease patients had moderate crisis, one presented with mild hemolytic anemia; however, the other 12 patients had a severe clinical presentation with frequent blood transfusion requirements, vaso occlusive crisis, avascular necrosis of the femur and febrile illness. The 4 HbSE disease patients had a mild to moderate presentation. Two of the 3 HbDPunjabE patients were asymptomatic with one patient's sibling having a mild presentation. The hemoglobin levels of the HbSDPunjab disease patients ranged from 2.3 to 8.5g/dl and MCV from 76.3 to 111.6fl. The hemoglobin levels of the HbDPunjabE and HbSE patients ranged from 10.8 to 11.9 and 9.8 to 10.0g/dl whereas MCV ranged from 67.1 to 78.2 and 74.5 to 76.0fl respectively. ConclusionsHbSDPunjab disease patients should be identified during newborn screening programmes and managed in a way similar to sickle cell disease. Couple at risk of having HbSDPunjab disease children may be given the option of prenatal diagnosis in subsequent pregnancies.