Development, validation and application of single molecule molecular inversion probe based novel integrated genetic screening method for 29 common lysosomal storage disorders in India.

BACKGROUND: Current clinical diagnosis pathway for lysosomal storage disorders (LSDs) involves sequential biochemical enzymatic tests followed by DNA sequencing, which is iterative, has low diagnostic yield and is costly due to overlapping clinical presentations. Here, we describe a novel low-cost and high-throughput sequencing assay using single-molecule molecular inversion probes (smMIPs) to screen for causative single nucleotide variants (SNVs) and copy number variants (CNVs) in genes associated with 29 common LSDs in India. RESULTS: 903 smMIPs were designed to target exon and exon-intron boundaries of targeted genes (n = 23; 53.7 kb of the human genome) and were equimolarly pooled to create a sequencing library. After extensive validation in a cohort of 50 patients, we screened 300 patients with either biochemical diagnosis (n = 187) or clinical suspicion (n = 113) of LSDs. A diagnostic yield of 83.4% was observed in patients with prior biochemical diagnosis of LSD. Furthermore, diagnostic yield of 73.9% (n = 54/73) was observed in patients with high clinical suspicion of LSD in contrast with 2.4% (n = 1/40) in patients with low clinical suspicion of LSD. In addition to detecting SNVs, the assay could detect single and multi-exon copy number variants with high confidence. Critically, Niemann-Pick disease type C and neuronal ceroid lipofuscinosis-6 diseases for which biochemical testing is unavailable, could be diagnosed using our assay. Lastly, we observed a non-inferior performance of the assay in DNA extracted from dried blood spots in comparison with whole blood. CONCLUSION: We developed a flexible and scalable assay to reliably detect genetic causes of 29 common LSDs in India. The assay consolidates the detection of multiple variant types in multiple sample types while having improved diagnostic yield at same or lower cost compared to current clinical paradigm.

Biallelic cGMP-dependent type II protein kinase gene (PRKG2) variants cause a novel acromesomelic dysplasia.

BACKGROUND: C-type natriuretic peptide (CNP), its endogenous receptor, natriuretic peptide receptor-B (NPR-B), as well as its downstream mediator, cyclic guanosine monophosphate (cGMP) dependent protein kinase II (cGKII), have been shown to play a pivotal role in chondrogenic differentiation and endochondral bone growth. In humans, biallelic variants in NPR2, encoding NPR-B, cause acromesomelic dysplasia, type Maroteaux, while heterozygous variants in NPR2 (natriuretic peptide receptor 2) and NPPC (natriuretic peptide precursor C), encoding CNP, cause milder phenotypes. In contrast, no variants in cGKII, encoded by the protein kinase cGMP-dependent type II gene (PRKG2), have been reported in humans to date, although its role in longitudinal growth has been clearly demonstrated in several animal models. METHODS: Exome sequencing was performed in two girls with severe short stature due to acromesomelic limb shortening, brachydactyly, mild to moderate platyspondyly and progressively increasing metaphyseal alterations of the long bones. Functional characterisation was undertaken for the identified variants. RESULTS: Two homozygous PRKG2 variants, a nonsense and a frameshift, were identified. The mutant transcripts are exposed to nonsense-mediated decay and the truncated mutant cGKII proteins, partially or completely lacking the kinase domain, alter the downstream mitogen activation protein kinase signalling pathway by failing to phosphorylate c-Raf 1 at Ser43 and subsequently reduce ERK1/2 activation in response to fibroblast growth factor 2. They also downregulate COL10A1 and upregulate COL2A1 expression through SOX9. CONCLUSION: In conclusion, we have clinically and molecularly characterised a new acromesomelic dysplasia, acromesomelic dysplasia, PRKG2 type (AMDP).

Trends of humoral immune responses to heterologous antigenic exposure due to vaccination & omicron SARS-CoV-2 infection: Implications for boosting.

Background & objectives: Vaccination and natural infection can both augment the immune responses against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), but how omicron infection has affected the vaccine-induced and hybrid immunity is not well studied in Indian population. The present study was aimed to assess the durability and change in responses of humoral immunity with age, prior natural infection, vaccine type and duration with a minimum gap of six months post-two doses with either ChAdOx1 nCov-19 or BBV152 prior- and post-emergence of the omicron variant. Methods: A total of 1300 participants were included in this observational study between November 2021 and May 2022. Participants had completed at least six months after vaccination (2 doses) with either ChAdOx1 nCoV-19 or an inactivated whole virus vaccine BBV152. They were grouped according to their age (≤ or ≥60 yr) and prior exposure of SARS-CoV-2 infection. Five hundred and sixteen of these participants were followed up after emergence of the Omicron variant. The main outcome was durability and augmentation of the humoral immune response as determined by anti-receptor-binding domain (RBD) immunoglobulin G (IgG) concentrations, anti-nucleocapsid antibodies and anti-omicron RBD antibodies. Live virus neutralization assay was conducted for neutralizing antibodies against four variants - ancestral, delta and omicron and omicron sublineage BA.5. Results: Before the omicron surge, serum anti-RBD IgG antibodies were detected in 87 per cent participants after a median gap of eight months from the second vaccine dose, with a median titre of 114 [interquartile range (IQR) 32, 302] BAU/ml. The levels increased to 594 (252, 1230) BAU/ml post-omicron surge (P<0.001) with 97 per cent participants having detectable antibodies, although only 40 had symptomatic infection during the omicron surge irrespective of vaccine type and previous history of infection. Those with prior natural infection and vaccination had higher anti-RBD IgG titre at baseline, which increased further [352 (IQR 131, 869) to 816 (IQR 383, 2001) BAU/ml] (P<0.001). The antibody levels remained elevated after a mean time gap of 10 months, although there was a decline of 41 per cent. The geometric mean titre was 452.54, 172.80, 83.1 and 76.99 against the ancestral, delta, omicron and omicron BA.5 variants in the live virus neutralization assay. Interpretation & conclusions: Anti-RBD IgG antibodies were detected in 85 per cent of participants after a median gap of eight months following the second vaccine dose. Omicron infection probably resulted in a substantial proportion of asymptomatic infection in the first four months in our study population and boosted the vaccine-induced humoral immune response, which declined but still remained durable over 10 months.

Amplicon-Based Nanopore Sequencing of Patients Infected by the SARS-CoV-2 Omicron (B.1.1.529) Variant in India.

We report the sequencing of SARS-CoV-2 Omicron variants from 75 patients, using nanopore long-read sequencing chemistry. These data show a range of mutations in spike glycoprotein that are both unique and common to other populations.

Development of Flow Injection Analysis Method for the Second-Tier Estimation of Succinylacetone in Dried Blood Spot of Newborn Screening.

Tyrosinemia type 1 (TYR1) is a devastating aminoacidopathy, leading to mortality without medical intervention. Although, detection and quantification of tyrosine in dried blood spot (DBS) is possible, but being a non-specific marker for TYR1 and its frequent association with transient neonatal tyrosinemia limits its applicability. Despite, Succinylacetone (SUAC) being a pathognomonic marker for TYR1, but not often detectable by routine newborn screening (NBS). We envisaged to determine SUAC in DBS by an in-house flow injection analysis method on a liquid chromatography/tandem mass spectrometry (LC-MS/MS). Succinylacetone was eluted from the residual 3.2 mm DBS of primary NBS by an extraction solution containing acetonitrile-water-formic acid mixture containing stable-isotope labelled internal standard (IS) for SUAC and hydrazine. Detection and quantification was performed by the mass spectrometer using multiple reaction monitoring mode at m/z 155.1 → 109.1 for SUAC and m/z 160.1 → 114.1 for the SUAC IS. The assay was linear over a calibration range of 0.122-117.434 µmol/L. The Intra-day and Inter-day precision and accuracy for the assay was determined at two different levels of SUAC (2.542 µmol/L and 14.641 µmol/L), which showed a coefficient of variation of (6.91% and 12.65%) and (8.57% and 12.27%) respectively. The accuracy also ranged between 101.2 and 103.87%.This method provided the necessary sensitivity, precision, accuracy, recovery and linearity and hence, has the potential to reduce the false positive, false negative results which significantly minimise the cost involved in the screening and follow up of TYR1 patients. SUPPLEMENTARY INFORMATION: The online version of this article (10.1007/s12291-020-00944-z) contains supplementary material, which is available to authorized users.

Aminoacid Profiling of Children with Severe Acute Malnutrition Pre and Post Nutritional Rehabilitation.

Malnutrition is a significant comorbidity in nearly one-third of the 8 million deaths in children under five years of age worldwide. Children with severe acute malnutrition have severely disturbed physiology and metabolism. Considering the vital importance of amino acids and the likely changes with the therapeutic diet, we aimed at evaluating these changes in children with SAM at baseline and after rehabilitation with a therapeutic diet at 14 days. Severe acute malnutrition defined as per WHO, for children between 6 months and 5 years with weight for height/length < -3SD of WHO charts, bilateral pitting edema, and mid-upper arm circumference (MUAC) < 1.5 cm. A total of 38 children were enrolled as cases, whereas the control group comprised of 37 children. Anthropometric measurement and estimation of amino acids in the blood were done at the baseline and after dietary rehabilitation. The individual levels of the essential and non-essential amino acids were significantly lower in the cases as compared to the controls, except for Aspartate and Threonine. The levels of amino acids increased significantly after dietary rehabilitation except for arginine, however not to the levels of those in controls. Most of the metabolites were reflective of maladaptation in SAM. Though nutritional rehabilitation of children with SAM improved the levels of amino acids, these levels were still low when compared to the controls, stipulating that complete metabolic recovery may take a longer duration of time. This necessitates the continuation of nutritional rehabilitation for a longer time and regular follow up of these children to ensure better compliance.

ASAH1 pathogenic variants associated with acid ceramidase deficiency: Farber disease and spinal muscular atrophy with progressive myoclonic epilepsy.

Farber disease and spinal muscular atrophy with progressive myoclonic epilepsy are a spectrum of rare lysosomal storage disorders characterized by acid ceramidase deficiency (ACD), resulting from pathogenic variants in N-acylsphingosine amidohydrolase 1 (ASAH1). Other than simple listings provided in literature reviews, a curated, comprehensive list of ASAH1 mutations associated with ACD clinical phenotypes has not yet been published. This publication includes mutations in ASAH1 collected through the Observational and Cross-Sectional Cohort Study of the Natural History and Phenotypic Spectrum of Farber Disease (NHS), ClinicalTrials.gov identifier NCT03233841, in combination with an up-to-date curated list of published mutations. The NHS is the first to collect retrospective and prospective data on living and deceased patients with ACD presenting as Farber disease, who had or had not undergone hematopoietic stem cell transplantation. Forty-five patients representing the known clinical spectrum of Farber disease (living patients aged 1-28 years) were enrolled. The curation of known ASAH1 pathogenic variants using a single reference transcript includes 10 previously unpublished from the NHS and 63 that were previously reported. The publication of ASAH1 variants will be greatly beneficial to patients undergoing genetic testing in the future by providing a significantly expanded reference list of disease-causing variants.

Gaucher disease: single gene molecular characterization of one-hundred Indian patients reveals novel variants and the most prevalent mutation.

BACKGROUND: Gaucher disease is a rare pan-ethnic, lysosomal storage disorder resulting due to beta-Glucosidase (GBA1) gene defect. This leads to the glucocerebrosidase enzyme deficiency and an increased accumulation of undegraded glycolipid glucocerebroside inside the cells' lysosomes. To date, nearly 460 mutations have been described in the GBA1 gene. With the aim to determine mutations spectrum and molecular pathology of Gaucher disease in India, the present study investigated one hundred unrelated patients (age range: 1 day to 31 years) having splenomegaly, with or without hepatomegaly, cytopenia and bone abnormality in some of the patients. METHODS: The biochemical investigation for the plasma chitotriosidase enzyme activity and ß-Glucosidase enzyme activity confirmed the Gaucher disease. The mutations were identified by screening the patients' whole GBA gene coding region using bidirectional Sanger sequencing. RESULTS: The biochemical analysis revealed a significant reduction in the ß-Glucosidase activity in all patients. Sanger sequencing established 71 patients with homozygous mutation and 22 patients with compound heterozygous mutation in GBA1 gene. Lack of identification of mutations in three patients suggests the possibility of either large deletion/duplication or deep intronic variations in the GBA1 gene. In four cases, where the proband died due to confirmed Gaucher disease, the parents were found to be a carrier. Overall, the study identified 33 mutations in 100 patients that also covers four missense mutations (p.Ser136Leu, p.Leu279Val, p.Gly383Asp, p.Gly399Arg) not previously reported in Gaucher disease patients. The mutation p.Leu483Pro was identified as the most commonly occurring Gaucher disease mutation in the study (62% patients). The second common mutations identified were p.Arg535Cys (7% patients) and RecNcil (7% patients). Another complex mutation Complex C was identified in a compound heterozygous status (3% patients). The homology modeling of the novel mutations suggested the destabilization of the GBA protein structure due to conformational changes. CONCLUSIONS: The study reports four novel and 29 known mutations identified in the GBA1 gene in one-hundred Gaucher patients. The given study establishes p.Leu483Pro as the most prevalent mutation in the Indian patients with type 1 Gaucher disease that provide new insight into the molecular basis of Gaucher Disease in India.

Genetic abnormalities in a large cohort of Coffin-Siris syndrome patients.

Coffin-Siris syndrome (CSS, MIM#135900) is a congenital disorder characterized by coarse facial features, intellectual disability, and hypoplasia of the fifth digit and nails. Pathogenic variants for CSS have been found in genes encoding proteins in the BAF (BRG1-associated factor) chromatin-remodeling complex. To date, more than 150 CSS patients with pathogenic variants in nine BAF-related genes have been reported. We previously reported 71 patients of whom 39 had pathogenic variants. Since then, we have recruited an additional 182 CSS-suspected patients. We performed comprehensive genetic analysis on these 182 patients and on the previously unresolved 32 patients, targeting pathogenic single nucleotide variants, short insertions/deletions and copy number variations (CNVs). We confirmed 78 pathogenic variations in 78 patients. Pathogenic variations in ARID1B, SMARCB1, SMARCA4, ARID1A, SOX11, SMARCE1, and PHF6 were identified in 48, 8, 7, 6, 4, 1, and 1 patients, respectively. In addition, we found three CNVs including SMARCA2. Of particular note, we found a partial deletion of SMARCB1 in one CSS patient and we thoroughly investigated the resulting abnormal transcripts.

Assessment of Interleukin-18 gene polymorphism and serum levels in oral lichen planus in an Indian population.

BACKGROUND: Oral lichen planus (OLP) is a chronic, inflammatory disease with uncertain etiology. The aim of this study was to assess Interleukin-18 (IL-18) gene polymorphism and serum levels in OLP cases of Indian origin and to compare them with a control population of similar background. METHODS: The assessment of single-nucleotide polymorphisms (SNPs) of IL-18 gene at promoter regions -137(G/C) and -607(C/A) was done in 70 OLP cases and 70 healthy controls using sequence-specific primer-polymerase chain reaction (SSP-PCR). In a subset of this cohort, comprising of 41 OLP cases and 41 controls, serum IL-18 levels were assessed using enzyme-linked immunosorbent assay (ELISA). RESULTS: Mean serum levels of IL-18 among OLP cases were significantly higher when compared to controls. Genotypic and allelic frequencies of IL-18 at position -137(G/C) showed that GG genotype and allele G was significantly higher in OLP cases, whereas, GC genotype and C allele was high in the control group. Polymorphism of IL-18 at position -607(C/A) showed no significant differences. CONCLUSIONS: Gene polymorphism at -137GG genotype and allele G seems to be associated with genetic susceptibility to OLP whereas -137GC and allele C may have a protective role against its development. However, our study lacks clear statistical correlation, the differences observed could be caused by sampling problems and the results could not be fully representative of Indian patients with OLP. Further studies are warranted to explore the role of IL-18 genetic polymorphisms in OLP development.

Detection of respiratory syncytial virus & Mycoplasma pneumoniae in paediatric lower respiratory tract infections.

Background & objectives: Respiratory syncytial virus (RSV) and Mycoplasma pneumoniae are considered common cause of lower respiratory tract infections (LRTIs) in children. The present study was conducted to detect M. pneumoniae and RSV in paediatric LRTIs employing serology, polymerase chain reaction (PCR) and reverse transcriptase PCR (RT-PCR) analysis. Methods: Seventy five children aged one month to five years with acute LRTIs were investigated for M. pneumoniae antibodies and RSV antigen using immunochromatographic test, RT-PCR for RSV and M. pneumoniae by PCR on nasopharyngeal aspirates. Results: RSV infection was observed in 33 (44%) and M. pneumoniae was positive in 26 (35%) children. No significant difference in infection was noted between male and female children. Clinical and radiological features among RSV and M. pneumoniae positive and negative cases were similar. Considering RT-PCR for RSV as gold standard, RSV antigen immunochromatography was 90.90 per cent sensitive and 100 per cent specific. Interpretation & conclusions: Our study showed the presence of RSV and M. pneumoniae infection in 44 and 35 per cent children, respectively with community-acquired LRTIs and aged less than five years.

Identification of a novel MKS locus defined by TMEM107 mutation.

Meckel-Gruber syndrome (MKS) is a perinatally lethal disorder characterized by the triad of occipital encephalocele, polydactyly and polycystic kidneys. Typical of other disorders related to defective primary cilium (ciliopathies), MKS is genetically heterogeneous with mutations in a dozen genes to date known to cause the disease. In an ongoing effort to characterize MKS clinically and genetically, we implemented a gene panel and next-generation sequencing approach to identify the causal mutation in 25 MKS families. Of the three families that did not harbor an identifiable causal mutation by this approach, two mapped to a novel disease locus in which whole-exome sequencing revealed the likely causal mutation as a homozygous splicing variant in TMEM107, which we confirm leads to aberrant splicing and nonsense-mediated decay. TMEM107 had been independently identified in two mouse models as a cilia-related protein and mutant mice display typical ciliopathy phenotypes. Our analysis of patient fibroblasts shows marked ciliogenesis defect with an accompanying perturbation of sonic hedgehog signaling, highly concordant with the cellular phenotype in Tmem107 mutants. This study shows that known MKS loci account for the overwhelming majority of MKS cases but additional loci exist including MKS13 caused by TMEM107 mutation.

Mutation Analyses in Selected Exons of the MUT Gene in Indian Patients with Methylmalonic Acidemia.

Deficiency or diminished activity of a cobalamin dependent enzyme methylmalonyl-CoA mutase causes inborn error of metabolism called methylmalonic acidemia (MMA). In this study we elucidated the spectrum of mutations in 21 Indian mut MMA patients by direct sequencing. Sequence analysis identified a total of 70 mutations in exon 2, 9, 11 and 12 of MUT gene. Out of which 26 mutations were predicted to be deleterious and rest were benign. The 23 novel mutations consist of four nonsense mutations (p.N6*, p.G539*, p.E609* and p.I671*), twelve missense mutations (p.K128I, p.N547T, p.D554Y, p.A558T, p.R559P, p.A631T, p.I647T, p.E656D, p.V657E, p.Q660H, p.K679N, and p.G696Y) and seven frame shift mutations (c.375_376insA, c.1642delA, c.1655delC, c.1825_1826insT, c.1957delGA, c.2014delA and c.2062_2063insGA). All of them are point mutations or micro rearrangements. Three of these mutations (p.K621N, p.G648D, p.G630E) have been previously reported; all of them are missense mutations. The mutations are distributed throughout the exon 2, 9, 11 and 12, 38.4 % mutation are located in exon 12.

Pendred Syndrome in a Newborn with Neck Swelling: A Case Report.

BACKGROUND: Pendred syndrome is a rare autosomal recessive condition, characterized by functional impairment of thyroid gland and sensorineural hearing loss. The syndrome presents in patients with homozygous or compound heterozygous mutation. The presentation in the form of neck mass in a newborn is rare. CASE CHARACTERISTICS: A 1 month old baby presented to us with neck mass, which was found to be an enlarged thyroid gland. Thyroid function tests were consistent with hypothyroidism. Further evaluation revealed moderate sensorineural hearing loss; genetic analysis showed that baby was homozygous for the known mutations causing the disease. INTERVENTION: Thyroid hormone replacement and hearing habilitation were done. Follow up showed regression of the neck mass and normalization of thyroid function tests. Genetic counseling of the family was done. MESSAGE: Identification of the exact cause of congenital hypothyroidism can prevent grave consequences later on for the patient as well as for the family.

Does angiotensin-converting enzyme-1 (ACE-1) gene polymorphism lead to chronic kidney disease among hypertensive patients?

BACKGROUND: Hypertension is one of the important contributing factors linked with both causation and development of kidney disease. It is a multifactorial, polygenic, and complex disorder due to interaction of several risk genes with environmental factors. The present study was aimed to explore genetic polymorphism in ACE-1 gene as a risk factor for CKD among hypertensive patients. METHODS: Three hundred patients were enrolled in the study. Ninety were hypertensive patients with CKD taken as cases, whereas 210 hypertensive patients without CKD were taken as controls. Demographic data including age, sex, Body mass index (BMI), and other risk factors were also recorded. DNA was extracted from blood by salting out method. Genotyping of ACE gene was done by PCR technique. All the statistical analysis was done by using Epi Info and SPSS version 16 software (SPSS Inc., Chicago, IL). RESULTS: Mean age was higher in the control group (p < 0.05). Variables among two groups were compared out of which age, BMI, hemoglobin (Hb) was found to be statistically significant whereas other variables like systolic blood pressure, triglyceride and low-density lipoprotein were not. Blood urea and serum creatinine levels were statistically significant in the two genotypes (p < 0.05). Total and HDL cholesterol were statistically significant for DD genotype of ACE gene (OR = 1.42, 95% CI = 0.72-2.81). Similarly, the risk for CKD among hypertensive patients was also associated with D allele of ACE gene (OR = 1.25, 95% CI = 0.86-1.79). CONCLUSION: It is concluded that ACE-DD genotype may be a risk factor for the causation and development of chronic kidney failure among hypertensive patients.

Polymorphism of 3' UTR of MAMLD1 gene is also associated with increased risk of isolated hypospadias in Indian children: a preliminary report.

OBJECTIVE: To study MAMLD1 gene polymorphisms, serum LH and testosterone levels amongst Indian children with isolated hypospadias (IH) and controls. MATERIALS AND METHODS: Screening of the MAMLD1 gene was performed by PCR sequencing method in 100 Indian children aged 0-12 years presenting with IH and 100 controls. LH and testosterone hormone levels were also assessed (categorized in four age-wise groups). RESULTS: IH subjects had significantly higher incidence of MAMLD1 polymorphism as compared to controls (33 vs 15 %, p = 0.01). Of various genomic variants identified in this study, the noteworthy novel ones were missense mutation P299A and single nucleotide polymorphism c.2960C>T in 3' UTR of Exon 7. While p 299A was found to cause protein structural instability consequent to amino acid change, eighty percent subjects with c.2960C>T in 3' UTR of Exon 7 (corresponding to newly discovered currently non-validated exon 11) were found to have lower testosterone levels when compared with their age group mean. IH showed statistically higher incidence of c.2960C>T in comparison to controls (22 vs 10 %, p value 0.046) and about 2.5-folds higher risk of this anomaly. CONCLUSION: Occurrence of MAMDL1 gene polymorphisms, specially of c.2960C>T in 3' UTR of its exon 7 is associated with a higher risk of IH in Indian children, probably by lowering androgenic levels.

Liquid-Liquid Extraction and Solid Phase Extraction for Urinary Organic Acids: A Comparative Study from a Resource Constraint Setting.

Pre analytical process of extraction for accurate detection of organic acids is a crucial step in diagnosis of organic acidemias by GCMS analysis. This process is accomplished either by solid phase extraction (SPE) or by liquid-liquid extraction (LLE). Both extraction procedures are used in different metabolic laboratories all over the world. In this study we compared these two extraction procedures in respect of precision, accuracy, percent recovery of metabolites, number of metabolites isolated, time and cost in a resource constraint setup. We observed that the mean recovery from SPE was 84.1 % and by LLE it was 77.4 % (p value <0.05). Moreover, the average number of metabolites isolated by SPE and LLE was 161.8 ± 18.6 and 140.1 ± 20.4 respectively. The processing cost of LLE was economical. In a cost constraint setting using LLE may be the practical option if used for organic acid analysis.

Expanding the genetic and phenotypic spectrum of popliteal pterygium disorders.

The popliteal pterygia syndromes are a distinct subset of the hundreds of Mendelian orofacial clefting syndromes. Popliteal pterygia syndromes have considerable variability in severity and in the associated phenotypic features but are all characterized by cutaneous webbing across one or more major joints, cleft lip and/or palate, syndactyly, and genital malformations. Heterozygous mutations in IRF6 cause popliteal pterygium syndrome (PPS) while homozygous mutations in RIPK4 or CHUK (IKKA) cause the more severe Bartsocas-Papas syndrome (BPS) and Cocoon syndrome, respectively. In this study, we report mutations in six pedigrees with children affected with PPS or BPS. Using a combination of Sanger and exome sequencing, we report the first case of an autosomal recessive popliteal pterygium syndrome caused by homozygous mutation of IRF6 and the first case of uniparental disomy of chromosome 21 leading to a recessive disorder. We also demonstrate that mutations in RIPK4 can cause features with a range of severity along the PPS-BPS spectrum and that mutations in IKKA can cause a range of features along the BPS-Cocoon spectrum. Our findings have clinical implications for genetic counseling of families with pterygia syndromes and further implicate IRF6, RIPK4, and CHUK (IKKA) in potentially interconnected pathways governing epidermal and craniofacial development.

Adverse pregnancy outcome in patients with low pregnancy-associated plasma protein-A: The Indian Experience.

AIM: The aim of our study was to examine the association of low pregnancy-associated plasma protein-A (PAPP-A) with adverse pregnancy outcome. MATERIAL AND METHODS: A total of 1640 consecutive pregnant women between 9(+5) and 13(+6) weeks of pregnancy were recruited. One hundred and thirty women with PAPP-A levels < 0.4 multiple of median were followed till delivery and the outcome information was obtained for fetal loss, birthweight, growth restriction, preterm birth, reduced liquor and development of pre-eclampsia. RESULTS: During the study period, 130 (7.92%) women had low PAPP-A and were considered as cases and 200 women with normal PAPP-A were controls. Intrauterine growth restriction was observed in 28 (21.54%) cases as compared to 10 (5%) controls. Pre-eclampsia presented in 24 (18.46%) cases and in 18 (9%) controls. Twenty (15.38%) cases had preterm delivery compared to 12 (6%) controls. Fifty-six (43.08%) cases delivered low-birthweight babies compared to 22 (11%) controls. Thus, the incidence of intrauterine growth restriction, preterm birth and low birthweight was significantly more in the cases as compared to the control group. CONCLUSIONS: PAPP-A is a valuable analyte for predicting risk of adverse pregnancy outcome and women with low serum PAPP-A levels would benefit from closer surveillance.