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Introduction: The placenta provides nutrients to the fetus, and it has protective effects against harmful substances. Unhealthy maternal diets and toxic agents might increase free radical (FR) production. Elevated FR levels are associated with a high risk of oxidative stress, which may cause DNA damage. DNA might be oxidized in the placenta, occasionally affecting its methylation profile due to 8-hidroxy-2'-deoxyguanosine formation., Methods: This study assessed 130 mothers and their children. The maternal's nutritional patterns were determined using the Food Frequency Questionnaire. Information on smoking and alcohol consumption was collected during the medical examination. Data on placental DNA were obtained to determine the MTHFR 677C/T genotype and the proportion of placental DNA methylation (pDNAm)., Results: Consumption of vitamins and folic acid was above 85%. The pDNAm was found to be correlated with gestational age and coffee intake. Mothers with a smoking history had a low pDNAm. Placentas with the TT genotype had a higher but not significant pDNAm. In the placentas with the CC/CT genotype, the pDNAm was positively associated with carbohydrate and biotin intake. However, the TT genotype was negatively associated with folate and vegetable intake., Discussion: The pDNAm was positively associated with coffee intake, but not with macro-, and micronutrient intake. However, it was negatively associated with cigarette smoking. The placentas with the CC/CT genotype had a lower pDNAm than those with the TT genotype. In the placentas with the CC/CT or TT genotype, methylation was positively, and negatively associated with micro- or macronutrients, respectively., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Background: Opitz GBBB syndrome (GBBB) is an X-linked disease characterized by midline defects, including congenital heart defects. We present our diagnostic approach to the identification of GBBB in a consanguineous family in which two males siblings were concordant for a total anomalous connection of pulmonary veins and minor facial dysmorphias., Methods: Targeted exome sequencing analysis of a 380-gene panel associated with cardiovascular disease was performed on the propositus. Interpretative analysis of the exome results was conducted, and 3D models of the protein changes were generated., Results: We identified a NM_000381.4:c.608G>A;p.(Arg203Gln) change in MID1, affecting the conformation of the B-box 2 domain of the protein, with a zinc finger structure and associated protein interactions. This clinical phenotype is consistent with GBBB; however, the type of congenital heart disease observed in this case has not been previously reported., Conclusion: A new likely pathogenic variant on MID1 c.608G>A was found to be associated with Opitz GBBB syndrome., (© 2023 The Authors. Molecular Genetics & Genomic Medicine published by Wiley Periodicals LLC.)

Thyroid nodules are the main indicators of thyroid cancer, their malignancy is evaluated by cytological analysis and imaging technology, however, there are still cases where the result is not enough to classify thyroid cancer. Therefore, there is a necessity for accurate molecular biomarkers to collaborate in the diagnosis. Here, we analyzed the mRNA relative expression of CLDN1, TIMP1, and KRT19 genes in FNA of malignant (n = 48) and benign (n = 49) thyroid nodules by RT-qPCR analysis to assess their predictive value as cancer biomarkers. We identified a significant overexpression of the three transcripts in malignant nodules, therefore, the evaluation of their predictive capacity to distinguish between benign and malignant nodule as individual biomarkers were evaluated by logistic regression tests, obtaining promising prediction results to rule out cancer; later by random forest to create a stronger model, we included expression results with clinicopathological characteristics, the best model consists of the three-mRNA level expression with patient's history of cancer (AUC = 0.821, accuracy = 85.4% and sensitivity of 81.1%). These results demonstrate a dysregulated expression of CLDN1, KRT19 and TIMP1 in thyroid cancer, thus, represent a promising panel of biomarkers to be evaluated in indeterminate thyroid nodules., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Overweight and obesity have become a world-health public problem, mainly for developing countries. Both health conditions have a higher prevalence among women of childbearing age. Physiopathology, overweight and obesity are characterized by a chronic oxidative stress status, which has deleterious effects on mothers and children. Hence, we determine whether the qualities of diet during pregnancy and maternal pregestational body mass index (BMI) are associated with increased oxidative stress markers in mothers and newborns. Two hundred forty-two (242) mother-newborn pairs were classified according to their pregestational BMI. Information on food intake was collected using a food frequency questionnaire in the third trimester of pregnancy. Levels of Malondialdehyde (MDA) and Nitric Oxide (NO) were measured in plasma from mothers at the end of the third trimester of pregnancy and from cord blood at birth. MDA and NO levels in mother-newborn pairs with maternal pregestational overweight or obesity were higher than in mother-newborn pairs with pregestational normal weight. For women (and newborns) who had a higher intake of fruit and vegetables, the levels of NO and MDA were lower. Lastly, women with pregestational obesity had lower fruit and vegetable intake during pregnancy and higher levels of oxidative stress and in their newborns.

The genome of the SARS-CoV-2 virus, the causal agent of the COVID-19 pandemic, has diverged due to multiple mutations since its emergence as a human pathogen in December 2019. Some mutations have defined several SARS-CoV-2 clades that seem to behave differently in terms of regional distribution and other biological features. Next-generation sequencing (NGS) approaches are used to classify the sequence variants in viruses from individual human patients. However, the cost and relative scarcity of NGS equipment and expertise in developing countries prevent studies aimed to associate specific clades and variants to clinical features and outcomes in such territories. As of March 2021, the GR clade and its derivatives, including the B.1.1.7 and B.1.1.28 variants, predominate worldwide. We implemented the post-PCR small-amplicon high-resolution melting analysis to genotype SARS-CoV-2 viruses isolated from the saliva of individual patients. This procedure was able to clearly distinguish two groups of samples of SARS-CoV-2-positive samples predicted, according to their melting profiles, to contain GR and non-GR viruses. This grouping of the samples was validated by means of amplification-refractory mutation system (ARMS) assay as well as Sanger sequencing.

Background: Focal dermal hypoplasia (FDH) is rare X-linked dominant disease characterized by atrophy and linear pigmentation of the skin, split hand/foot deformities and ocular anomalies. FDH is caused by mutations of the Porcupine (PORCN) gene, which encodes an enzyme that catalyzes the palmitoylation of Wnt ligands required for their secretion. High resolution melting analysis (HRM) is a technique that allows rapid, labor-efficient, low-cost detection of genomic variants. In the present study, we report the successful implementation of HRM in the molecular diagnosis of FDH., Methods: Polymerase chain reaction and HRM assays were designed and optimized for each of the coding exons of the PORCN gene, processing genomic DNA samples form a non-affected control and a patient complying with the FDH diagnostic criteria. The causal mutation was characterized by Sanger sequencing from an amplicon showing a HRM trace suggesting heterozygous variation and was validated using an amplification-refractory mutation system (ARMS) assay., Results: The melting profiles suggested the presence of a variant in the patient within exon 1. Sanger sequencing revealed a previously unknown C to T transition replacing a glutamine codon for a premature stop codon at position 28, which was validated using ARMS., Conclusions: Next-generation sequencing facilitates the molecular diagnosis of monogenic disorders; however, its cost-benefit ratio is not optimal when a single, small or medium size causal gene is already identified and the clinical diagnostic presumption is strong. Under those conditions, as it is the case for FDH, HRM represents a cost- and labor-effective approach., (© 2020 John Wiley & Sons, Ltd.)

Traditional peer review is undergoing increasing questioning, given the increase in scientific fraud detected and the replication crisis biomedical research is currently going through. Researchers, academic institutions, and research funding agencies actively promote scientific record analysis, and multiple tools have been developed to achieve this. Different biomedical journals were founded with post-publication peer review as a feature, and there are several digital platforms that make this process possible. In addition, an increasing number biomedical journals allow commenting on articles published on their websites, which is also possible in preprint repositories. Moreover, publishing houses and researchers are largely using social networks for the dissemination and discussion of articles, which sometimes culminates in refutations and retractions., La revisión por pares tradicional atraviesa por crecientes cuestionamientos, dado el aumento en el fraude científico detectado y la crisis de replicación que recientemente se ha presentado en la investigación biomédica. Investigadores, instituciones académicas y agencias de financiamiento activamente promueven el análisis del registro científico y se han desarrollado múltiples herramientas para lograrlo. Diferentes revistas biomédicas se fundaron con la revisión por pares pospublicación como característica; existen varias plataformas digitales que hacen posible este proceso. Asimismo, cada vez hay más revistas biomédicas que permiten comentar artículos publicados en sus sitios web, lo cual también es posible en repositorios de preimpresiones. Sumado a esto, las casas editoriales y los investigadores están usando ampliamente las redes sociales para la difusión y discusión de artículos, lo cual a veces culmina en refutaciones y retracciones., (Copyright: © 2020 Permanyer.)

Background: 22q11.2 deletion syndrome is a medical condition that results from genomic loss at chromosome 22. Affected patients exhibit large variability that ranges from a severe condition to mild symptoms. In addition, the spectrum of clinical features differs among populations and even within family members. The facial features related to this syndrome are not an exception, and although part of its variation arises through development, few studies address this topic in order to understand the intra and inter-population heterogeneities. Here, we analyze the ontogenetic dynamics of facial morphology of Mexican patients with del22q11.2 syndrome., Methods: Frontal facial photographs of 37 patients (mean age = 7.65 ± 4.21 SE) with del22q11.2DS and 200 control subjects (mean age = 7.69 ± 4.26 SE) were analyzed using geometric morphometric methods. Overall mean shape and size differences between patients and controls were analyzed, as well as differences in ontogenetic trajectories (i.e. development, growth, and allometry)., Results: We found that Mexican patients show typical traits that have been reported for the Caucasian population. Additionally, there were significant differences between groups in the facial shape and size when all the ontogenetic stages were considered together and, along ontogeny. The developmental and allometric trajectories of patients and controls were similar, but they differed in allometric scaling. Finally, patients and controls showed different growth trajectories., Conclusion: The results suggest that the typical face of patients with del22q11.2DS is established prenatally; nonetheless, the postnatal ontogeny could influence the dysmorphology and its variability through size-related changes.

Background: MicroRNAs (miRNAs) modulate gene expression through destabilization or translational inhibition of cytoplasmic transcripts or by transcriptional regulation through binding to genomic DNA. Although miRNAs are globally down-regulated in cancer, some are overexpressed in neoplastic tissues, playing key roles in tumorigenesis (oncomiRs), sometimes behaving as effective cancer markers., Methods: Using total RNA from human uterus adenocarcinoma and non-neoplastic uterus, we conducted a small RNA-sequencing experiment followed by prediction of novel miRNAs using MirDeep* software. Synteny analysis and whole genome alignments were performed using BLAST. We also evaluated expression by a reverse transcriptase-polymerase chain reaction (RT-PCR) in normal tissues of the FSD2 gene, which spans the human miR-1839-5p gene in the opposite direction., Results: MirDeep* analysis predicted a miRNA not previously annotated in databases, identical to and likely the orthologue of mouse miR-1839-5p. Whole-genome local alignments of this miRNA revealed a single perfect hit that is indeed syntenic to mouse miR-1839-5p. Alignments with other mammalian orthologues showed considerable conservation. We validated the prediction via a stem-loop RT-PCR assay, also employed to screen RNA samples from several additional normal and cancer tissues, showing increased expression in neoplastic tissues compared to their respective non neoplastic counterparts. Human heart tissue expresses both miR-1839-5p and FSD2., Conclusions: Human tissues express an orthologue of mouse miR-1839-5p and, given its expression pattern, we suggest that this miRNA could be explored as a potential oncomiR or cancer marker. Also, according to the genomic organization of miR-1839-5p and FSD2, perfect complementarity exists between the two elements, making possible miRNA-directed cleavage in human cardiac tissue., (© 2019 John Wiley & Sons, Ltd.)

Background and Objective: Genetics play a very strong role in the development of pediatric-onset type 2 diabetes (T2D); however, little information exists about specific common single nucleotide polymorphisms (SNPs) associated with T2D in this age group. The aim of the study was to analyze the association and parental transmission of 64 obesity-related SNPs with pediatric-onset T2D in Mexican families., Methods: A total of 57 pedigrees containing 171 probands with pediatric-onset T2D and 119 unrelated controls older than 18 years were included. The participants were genotyped for 64 polymorphisms. Association of each variant with pediatric-onset T2D was analyzed through a parent-offspring transmission disequilibrium test (TDT) and in a case-control comparison by χ 2 analysis., Results: Five SNPs exhibited associations with pediatric-onset T2D in the combined case-parent trio and case-control analysis: LINGO/rs10968576 (odds ratio [OR] 1.82, P = 0.003), POC5/rs2112347 (OR 1.96, P = 2.4E-5), RPS10-NUDT3/rs206936 (OR 1.40, P = 0.023), GLIS3/rs7034200 (OR 2.34, P = 1.2E-6), and VEGFA/rs6905288 (OR 1.58, P = 0.015). The first three were also associated with obesity status. The SNPs POC5/rs2112347 and RPS10-NUDT3/rs206936 were significantly associated through the maternal allele and GLIS3/rs7034200 through the paternal allele (P < 0.05)., Conclusions: These findings suggest that certain SNPs associated with obesity and other metabolic traits may also be involved in risk of pediatric-onset T2D in Mexican families. We also identified preferential transmission of parental alleles in some variants., (© 2019 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Objective To compare the level of oxidative deoxyribonucleic acid (DNA) damage (genotoxicity) between the offspring of mothers with and without diabetes diagnosed during pregnancy and its association with maternal body mass index (BMI). Methods We measured 8-hydroxy-deoxyguanosine (8-OH-dG), a marker of DNA oxidative damage, in venous umbilical cord plasma from newborns of mothers with (n=34) and without (n=56) diabetes diagnoses obtained during pregnancy. Two markers of oxidative stress - namely, nitric oxide degradation products (NOx) and total glutathione (GSH) - were quantified in both mothers and newborns. The effects of BMI, glycated hemoglobin (HbA1c), age and delivery mode were also analyzed. Results Newborns of mothers with diabetes during pregnancy exhibited higher levels of 8-OH-dG than those of mothers without diabetes (P<0.001). The other markers of oxidative stress were also higher in both mothers with diabetes and their newborns, with the exception of NOx in the mothers. The association of diabetes with 8-OH-dG was independent of other analyzed factors. Conclusion The offspring of mothers with diabetes during pregnancy are born with increased genotoxicity than the offspring of mothers without diabetes. BMI and HbA1c display an independent association with 8-OH-dG, particularly in the offspring of mothers not diagnosed with diabetes.

Objective: To determine the prevalence and spectrum of diseases that predispose to sudden cardiac death in Mexican children, and to identify the main early signs and symptoms that can enable the health personnel to suspect these diseases and to refer the patients to a tertiary hospital in a timely manner., Methods: Incidence, prevalence, and period prevalence, as well as early symptoms, clinical data, and follow-up were recorded on all children found with diseases that predispose to sudden cardiac death in The Children's Hospital of Mexico., Results: The study included 59 patients, with a mean age of 8 ± 5 years old, with 40 cardiomyopathies, and 19 with inherited arrhythmogenic diseases. The period prevalence was 9.5/1,000 patients/year. The most common early symptoms were dyspnoea, palpitations, and syncope. A Mendelian inheritance pattern was found in 9 cases. Three patients died of sudden cardiac death during the period of the study., Conclusion: Diseases that predispose to sudden cardiac death in children are not very well known by the general medical community. Every child with dyspnoea, palpitations and/or syncope, should be referred for the intensive search of these diseases. A complete cardiological evaluation in all members of the family is indicated., (Copyright © 2017 Instituto Nacional de Cardiología Ignacio Chávez. Publicado por Masson Doyma México S.A. All rights reserved.)

The incidence of total anomalous pulmonary venous connection (TAPVC) in the Caucasian population is 2.5/100,000 live births (LB), and the incidence in the Hispanic population is 19.8/100,000 LB. Without knowing the exact etiology for the development of congenital heart disease, our objective was to determine the maternal factors associated with the development of TAPVC., Methods: 55 mother-child binomials with isolated TAPVC (group I) and 152 healthy mother-child binomials (group II) were included. Both groups had no maternal history of addiction, pre-eclampsia, or type 1, 2 or gestational diabetes mellitus. Complete clinical histories were obtained for the women in both groups and perinatal and birth data were recorded. In addition, genealogies across three generations were constructed to determine affected first- or second-degree relatives with complex congenital heart disease., Results: Among the maternal characteristics analyzed, women in group I had a higher number of pregnancies before gestation of the index case (p = <0.05), and the Body Mass Index (BMI) before pregnancy was higher compared to Group II (p < 0.05), with an adjusted risk of OR = 3.6 (p = 0.011). The family history showed a higher prevalence in the group of patients with TAPVC compared to healthy children (p < 0.05)., Conclusion: Maternal obesity before pregnancy is a risk factor for the development of CATVP in children in the Mexican population., (Copyright © 2018 IMSS. Published by Elsevier Inc. All rights reserved.)

Introduction: Velocardiofacial syndrome (VCFS) is the most common microdeletion syndrome with an incidence of 1:4000 live births. Its phenotype is highly variable with facial, velopharyngeal, cardiac, endocrine, immunologic and psychiatric abnormalities. It is caused by a microdeletion in chromosome 22q11.2., Objectives: We present 7 years of experience evaluating patients with VCFS regarding their main clinical characteristics., Material and Methods: The patients included were multidisciplinary evaluated and had a positive FISH analysis for del22q11.2., Results: A total of 62 patients were assessed, a 34 female/28 male ratio was observed with ages ranging from 9 days to 16 years, all but one patient had typical facial features. A diagnosis of congenital heart disease was established in 97% of the patients; other clinical characteristics were identified with different percentages such as cleft palate, and hypocalcaemia. Three cases had a familial presentation., Discussion: While the clinical findings of this study were in general terms in keeping with the literature, it is interesting the unexpectedly high percentage of congenital heart disease identified in Mexican children with VCFS that also was the main cause for clinical referral., (Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.)

Objective: Obesity before pregnancy is associated with a greater risk for the offspring to develop obesity and diabetes in childhood and adulthood. The aim of the present study was to determine the association between maternal overweight or obesity before pregnancy and newborn oxidative stress (OS)., Methods: Seventy-two mother-child pairs were divided according to the pre-gestational body mass index (BMI) of the mothers as follows: eutrophic (n = 21), overweight (n = 32), and obese (n = 19). Malondialdehyde (MDA) and nitric oxide (NO) were measured in the plasma of a blood sample from the newborn's umbilical cord., Results: The MDA levels of newborns increased with maternal BMI (P = 0.001), as did the levels of NO (P = 0.019). There was a direct correlation between MDA and NO levels in each of the three groups (eutrophic: R(2)  = 0.59, P < 0.001; overweight: R(2)  = 0.45, P < 0.001; and obese: R(2)  = 0.26, P = 0.024)., Conclusions: Maternal overweight and obesity before pregnancy are associated with increased OS in the offspring., (© 2015 The Obesity Society.)

Background: Interleukin-1 receptor antagonist polymorphism (ILRN) 2 (ILRN*2) has been associated with a poor outcome in septic patients because of an elevated production of anti-inflammatory cytokines. In >70% of patients, morbidity and mortality in childhood acute lymphoblastic leukemia is caused by infections. The aim of this study was to determine the association between this polymorphism and the frequency of septic shock from the time of diagnosis until completion of treatment., Methods: This cohort study was conducted in 57 consecutive children with acute lymphoblastic leukemia. At the end of follow-up, children were stratified according to their IL1RN polymorphism (ILRN*1/ILRN*2), evaluating the impact of genotype on the severity of febrile neutropenic events during their treatment., Results: Overall survival was 80% at 55 months after treatment. The average number of febrile neutropenic events in this cohort was 2.82 per patient. Genotype distribution was 50.9% for homozygote IL-1RN*1, 38.6% for heterozygote ILRN*1/ILRN*2 and 10.5% for homozygote IL-1RN*2. The risk of presenting septic shock for homozygote IL1RN*2/IL1RN*2 and heterozygote ILRN*1/ILRN*2 patients was significantly greater (odds ratio, 45; P = 0.001) adjusted for age, gender, risk of leukemia and presence of pathogenic bacteria. Genotype IL-1RN*2 is associated with the risk of development of septic shock in children with acute lymphoblastic leukemia. Further research in larger population-based studies is needed to replicate these findings., Conclusions: This information would allow us to identify more predictive factors in this group of acute lymphoblastic leukemia patients in whom this information is lacking to establish an earlier and more aggressive approach.

Congenital heart defects (CHD) are the third leading cause of death in children <1 year of age in Mexico where there is a high prevalence of the 677C → T polymorphism of the MTHFR gene. This is important because the homozygous 677T/T MTHFR gene and deficiency of folic acid (FA) intake have been associated with CHD. Our objective was to analyze the possible association between the genotype 677T/T of the MTHFR gene and supplementation of FA in Mexican women with the presence of complex CHD in their children. We analyzed genotypes of 31 mothers of children with complex CHD (group I) and 62 mothers of healthy children (group II) and investigated FA supplementation during pregnancy in both study groups. Allele frequencies in group I were 41.9 % for C and 58.1 % for T and 22.6 % for genotype frequencies CC, 38.7 % for CT, and 38.7 % for TT. Allele frequencies in group II were 63.7 % for C and 36.3 % for T and 38.7 % for genotype frequencies CC, 50 % for CT and 11.3 % for TT. Both populations are in Hardy-Weinberg equilibrium. Odds ratio for having a child with a complex CHD was 5.9, p = 0.008 (95 % CI 1.67; 20.63) for the TT genotype. FA supplementation at any time during pregnancy was 90.3 and 87.9 % in groups II and I respectively (p > 0.05). Association was found between the maternal genotype (677/TT MTHFR) with the presence of complex CHD in their offspring. No differences in FA supplementation during any stage were found between groups.

Introduction and Objectives: The frequency of the 677C>T mutation in the methylenetetrahydrofolate reductase gene in Mexico is one of the highest worldwide. Some studies have shown that both the homozygous state of this mutation and a high homocysteine concentration are associated with congenital heart disease. The aim of this study was to determine whether this association exists in the Mexican population., Methods: Genotypes were analyzed in 60 patients with congenital heart disease and in their mothers, and the levels of homocysteine were determined in the latter group. The genotypes were compared with those of a control group (n=62) and of their mothers. All the possible mother-child genotype combinations were also compared., Results: There were no significant differences in allele or genotype frequencies between the patients with congenital heart disease and the controls or their respective mothers (P>.05). Although no significant differences were observed when the homocysteine concentrations in the presence of the CC or the TT genotype were compared, a clear trend was observed (P=.0621). We found no significant differences in homocysteine concentrations in relation to folic acid intake. The study cases and controls did not differ in terms of the possible combinations of mother-child genotypes., Conclusions: The frequencies obtained were consistent with those reported for Mexico. No significant differences were found between groups. Nor did we find any association between TT mutations in both the mother and child and hyperhomocysteinemia. There was no evidence of an association between any of the mother-child genotype combinations and congenital heart disease. Similar studies with larger numbers of patients are required to confirm or refute some of the trends observed in this report., (Copyright © 2011 Sociedad Española de Cardiología. Published by Elsevier Espana. All rights reserved.)

Objective: The goals of this population genetics study were to describe mtDNA haplogroups and ABO and Rh blood group systems of 3 Native Mexican populations, to determine their genetic variability, and to compare their haplogroups with those of 13 Native Mexican populations previously reported., Material and Methods: The three communities under analysis were a Tepehua-speaking community from Huehuetla (Hidalgo state), an Otomi-speaking community from San Antonio el Grande (Hidalgo state), and a Zapotec-speaking community from Juchitán (Oaxaca state). Every subject studied in each community had four grandparents who were born in the same community and spoke the same language. The four Amerindian mtDNA haplogroups (A, B, C and D) were studied by restriction analysis and gel electrophoresis., Results: Regarding the blood groups, the O group was the most frequent in the three populations (97.2, 94.7, and 86.2%, respectively), as well as the Rh+ group (100, 100, 84%). The three populations analyzed were in Hardy-Weinberg equilibrium. In respect to the mtDNA haplogroups, A, B, C and D, their percentage was 33.3, 36.1, 13.9 and 5.6 % in Huehuetla; 39.5, 13.2, 39.5 and 2.6 % in San Antonio el Grande, and 55.3, 21.0, 7.9 and 5.2 % in Juchitán. Between 5 and 11% of the haplogroups were of non-Amerindian origin, probably due to admixture with Caucasian and African populations, as has been reported in the past. No statistically-significant differences were found among the three populations studied or between them and 13 previously reported Native Mexican populations.

We describe a patient who had multiple malformations including ventriculomegaly, colpocephaly, corpus callosum, cerebellum and vermix hypoplasia, optic nerve hypoplasia, corneal opacity and congenital heart disease in whom a trisomy 1q32-qter and monosomy 5p derived from a t(1;5)mat was diagnosed by karyotype and FISH analysis. This trisomy/monosomy association has not been previously reported. The familial analysis of the translocation was carried out in four generations and its implications on the phenotype of the patient and genetic counseling are discussed.

There have only been eight patients with 6p pure trisomy involving different segments: four cases resulted from a translocation or insertion and four were due to an intrachromosomal duplication. We report here the first postnatally ascertained patient with a pure 6p partial trisomy due to an interchromosomal insertion (16;6)(p12;p21.2p23)mat. This rearrangement was confirmed by fluorescent in situ hybridization (FISH) with whole chromosome 6 and 16 painting probes. The clinical findings in the present patient were similar to those observed in previous cases, including craniofacial dysmorphism, minor anomalies, and lack of severe anatomical defects; yet, the unspecificity of many of these features prevented us from delineating the 6p pure trisomy syndrome.

Introduction: Maternal diabetes mellitus affects approximately 5% of all pregnancies. Pregestational diabetes mellitus has been associated with a high risk of spontaneous abortions and congenital malformations during the first trimester of pregnancy then is considered teratogenic. This frequency of birth defects is three to fivefold increased compared with general population. Although an association of gestational diabetes mellitus (GDM) with an increase of congenital malformations has not been demonstrated, some clinical and epidemiological studies of this possible association have reported the presence of GDM in mothers of children with congenital malformations., The Objective: Of this study was to compare the prevalence of congenital malformations associated with GDM in relation to pregestational diabetes mellitus and general population., Materials and Methods: In the present study 3 groups were compared: the group I was integrated by 112 new born of mothers with GDM; in the group 2, there were 30 new born from women with gestational diabetes mellitus. 103 new born from healthy women integrated the group 3. All patients were recruited consecutively during a period of 18 months., Results: A total of 24 cases with congenital malformations were detected. The group with the higher prevalence was the group 2 (30%). We found a tendency to a higher risk of congenital malformations on the cases exposed to GDM (group 1) compared with the group not exposed (group 3). The analysis of the mothers background of the children from group 2 with congenital malformations showed a significant difference in the antecedent of previous macrosomic product in comparison with the antecedents of the mothers of the same group that bear healthy babies., Comment: The results of the analysis in the studied population did not show an association between GDM and congenital malformations, although there is a tendency to a higher prevalence in comparison with not exposed population. This could be due to the heterogeneity of the GDM; an entity usually detected late in pregnancy, but probably present since the first weeks of gestation when the teratogenic effect could occur., Conclusion: In the present study we found that the antecedent of previous macrosomic products is an important risk factor, therefore, such women require a close vigilance of the glucose levels before and during the first weeks of pregnancy in order to prevent congenital malformations, one of the principal causes of death in the new born.

Cantú syndrome (CS) is characterized by congenital hypertrichosis, osteochondrodysplasia, cardiomegaly, and coarse facial appearance; autosomal recessive inheritance has been postulated. We report on a Mexican family with CS; the affected members are the 44-year-old father and his two children (a male and female), aged 14 and 4 years, respectively; each shows the classic characteristics, but the father and the brother also have a previously unreported feature, namely, a thick calvarium. This is the first reported instance of male-to-male transmission of CS. With the paternal age effect found in the reported sporadic cases and the segregation analysis [Robertson et al., 1999], autosomal dominant inheritance is more likely than autosomal recessive inheritance. The cases of affected sibs reported by Cantú et al. [1982] could be explained by parental gonadal mosaicism., (Copyright 2000 Wiley-Liss, Inc.)