A large, ten-generation family with autosomal dominant preaxial polydactyly/triphalangeal thumb: Historical, clinical, genealogical, and molecular studies.

We present a large, ten-generation family of 273 individuals with 84 people having preaxial polydactyly/triphalangeal thumb due to a pathogenic variant in the zone of polarizing activity regulatory sequence (ZRS) within the exon 5 of LMBR1. The causative change maps to position 396 of the ZRS, located at position c.423 + 4909C > T (chr7:156791480; hg38; LMBR1 ENST00000353442.

Deep Phenotyping and Genetic Characterization of a Cohort of 70 Individuals With 5p Minus Syndrome.

Chromosome-5p minus syndrome (5p-Sd, OMIM #123450) formerly known as syndrome results from the loss of genetic material at the distal region of the short arm of chromosome 5. It is a neurodevelopmental disorder of genetic cause. So far, about 400 patients have been reported worldwide.

Wolf-Hirschhorn Syndrome Candidate 1 Is Necessary for Correct Hematopoietic and B Cell Development.

Immunodeficiency is one of the most important causes of mortality associated with Wolf-Hirschhorn syndrome (WHS), a severe rare disease originated by a deletion in chromosome 4p. The WHS candidate 1 (WHSC1) gene has been proposed as one of the main genes responsible for many of the alterations in WHS, but its mechanism of action is still unknown. Here, we present in vivo genetic evidence showing that Whsc1 plays an important role at several points of hematopoietic development.

Deletion 1q43-44 in a patient with clinical diagnosis of Warburg-Micro syndrome.

Warburg-Micro syndrome (WARBM) is an autosomal recessive syndrome characterized by microcephaly, microphthalmia, microcornea, congenital cataracts, optic atrophy and central nervous system malformations. This syndrome is caused by mutations in the RAB3GAP1/2 and RAB18 genes, part of the Rab family, and in the TBC1D20 gene, which contributes to lipid droplet formation/metabolism. Here we present a patient with clinical diagnosis of WARBM syndrome, who did not have mutations in either the RAB3GAP1/2 genes, in the main exons of RAB18, nor in the TBC1D20 gene.

Delineation of the clinically recognizable 17q22 contiguous gene deletion syndrome in a patient carrying the smallest microdeletion known to date.

We describe a patient with a 1.34 Mb microdeletion at chromosome band 17q22, which is also present in his affected mother. To better delineate this microdeletion syndrome, we compare the clinical and molecular characteristics of 10 previously reported cases and our patient.

European recommendations for primary prevention of congenital anomalies: a joined effort of EUROCAT and EUROPLAN projects to facilitate inclusion of this topic in the National Rare Disease Plans.

Congenital anomalies (CA) are the paradigm example of rare diseases liable to primary prevention actions due to the multifactorial etiology of many of them, involving a number of environmental factors together with genetic predispositions. Yet despite the preventive potential, lack of attention to an integrated preventive strategy has led to the prevalence of CA remaining relatively stable in recent decades. The 2 European projects, EUROCAT and EUROPLAN, have joined efforts to provide the first science-based and comprehensive set of recommendations for the primary prevention of CA in the European Union.

Interstitial deletion 14q22.3-q23.2: genotype-phenotype correlation.

The increasing use of molecular tools in genetic diagnosis has produced a surge in the detection of genomic imbalances. Among the growing number of newly discovered chromosome alterations are the interstitial deletions 14q21-q23. In previous reports of this deletion, the patients appear to share ocular defects, pituitary alterations and hand/foot anomalies.

Haploinsufficiency of BMP4 gene may be the underlying cause of Frías syndrome.

In 2005, we reported on a family as having Frías syndrome (OMIM: 609640), with four affected members displaying a pattern of congenital defects nearly identical to those observed in a mother and son described by Frias [Frías et al. (1975). Birth Defects Orig Artic Ser 11:30-33].

Patient with disorganization syndrome: surgical procedures, pathology, and potential causes.

Background: The human disorganization syndrome (HDS) is an extremely rare malformation syndrome that presents with a severe pattern of defects affecting different structures.

Methods: We describe a newborn girl presenting with HDS. Her clinical features included a large appendage arising from the right buttock as the only alteration, with size and shape of a lower member-like structure, and a pedicle of the extra limb structure.

A 2.84 Mb deletion at 21q22.11 in a patient clinically diagnosed with Marden-Walker syndrome.

We present a girl with the characteristic clinical picture associated with Marden-Walker syndrome (MWS; OMIM 248700), including mask-like face with blepharophimosis, joint contractures, intellectual disability, a multicystic dysplastic kidney and cerebral dysgenesis. The long-term follow-up allowed us to monitor the evolution of the phenotype in this patient, and among the main findings we highlight the following: demyelination of the pyramidal tract demonstrated by transcranial magnetic stimulation and the involvement of the levator muscles of angle of mouth in fixed facial expression with relative integrity of the rest of the facial expression muscles. A 244 k array comparative genomic hybridization (aCGH) was carried out and showed a de novo interstitial deletion of approximately 2.

Assessing pre-implantation embryo development in mice provides a rationale for understanding potential adverse effects of ART and PGD procedures.

Although the molecular events controlling human pre-implantation development remain unclear, mechanisms have been identified by analyzing these stages in mice. Through this approach, considerable insight has been gained into the events that operate to determine the first two cell fate decisions, occurring from zygote formation to the blastocyst prior to implantation. These mechanisms are related to cell polarization, cell division, cell-cell contact, and cell spatial position.

[The thalidomide experience: review of its effects 50 years later].

This year is the 50(th) anniversary of the discovery that the drug thalidomide causes birth defects and should therefore be considered as a teratogen. However, despite the existence of several other drugs that are also human teratogens, thalidomide continues to cause concern among health professionals as well as the general population. The objectives of this article are to make a short historical review of the discovery that this drug severely alters the embryo development, the critical period of gestation and the identification of the real effect of thalidomide.

Amelia: a multi-center descriptive epidemiologic study in a large dataset from the International Clearinghouse for Birth Defects Surveillance and Research, and overview of the literature.

This study describes the epidemiology of congenital amelia (absence of limb/s), using the largest series of cases known to date. Data were gathered by 20 surveillance programs on congenital anomalies, all International Clearinghouse for Birth Defects Surveillance and Research members, from all continents but Africa, from 1968 to 2006, depending on the program. Reported clinical information on cases was thoroughly reviewed to identify those strictly meeting the definition of amelia.

Acardia: epidemiologic findings and literature review from the International Clearinghouse for Birth Defects Surveillance and Research.

Acardia is a severe, complex malformation of monozygotic twinning, but beyond clinical case series, very few epidemiologic data are available. The goals of this study were to assess the epidemiologic characteristics of acardia from birth defect registries in the International Clearinghouse for Birth Defects Surveillance and Research (Clearinghouse), and compare these findings to current literature. The study included 17 surveillance programs of the Clearinghouse representing 23 countries from North and South America, Europe, China, and Australia.

Sirenomelia: an epidemiologic study in a large dataset from the International Clearinghouse of Birth Defects Surveillance and Research, and literature review.

Sirenomelia is a very rare limb anomaly in which the normally paired lower limbs are replaced by a single midline limb. This study describes the prevalence, associated malformations, and maternal characteristics among cases with sirenomelia. Data originated from 19 birth defect surveillance system members of the International Clearinghouse for Birth Defects Surveillance and Research, and were reported according to a single pre-established protocol.

Conjoined twins: a worldwide collaborative epidemiological study of the International Clearinghouse for Birth Defects Surveillance and Research.

Conjoined twins (CT) are a very rare developmental accident of uncertain etiology. Prevalence has been previously estimated to be 1 in 50,000 to 1 in 100,000 births. The process by which monozygotic twins do not fully separate but form CT is not well understood.

Phocomelia: a worldwide descriptive epidemiologic study in a large series of cases from the International Clearinghouse for Birth Defects Surveillance and Research, and overview of the literature.

Epidemiologic data on phocomelia are scarce. This study presents an epidemiologic analysis of the largest series of phocomelia cases known to date. Data were provided by 19 birth defect surveillance programs, all members of the International Clearinghouse for Birth Defects Surveillance and Research.

Characterization of a 8q21.11 microdeletion syndrome associated with intellectual disability and a recognizable phenotype.

We report eight unrelated individuals with intellectual disability and overlapping submicroscopic deletions of 8q21.11 (0.66-13.

Molecular mechanisms generating and stabilizing terminal 22q13 deletions in 44 subjects with Phelan/McDermid syndrome.

In this study, we used deletions at 22q13, which represent a substantial source of human pathology (Phelan/McDermid syndrome), as a model for investigating the molecular mechanisms of terminal deletions that are currently poorly understood. We characterized at the molecular level the genomic rearrangement in 44 unrelated patients with 22q13 monosomy resulting from simple terminal deletions (72%), ring chromosomes (14%), and unbalanced translocations (7%). We also discovered interstitial deletions between 17-74 kb in 9% of the patients.

A clinical and experimental overview of sirenomelia: insight into the mechanisms of congenital limb malformations.

Sirenomelia, also known as sirenomelia sequence, is a severe malformation of the lower body characterized by fusion of the legs and a variable combination of visceral abnormalities. The causes of this malformation remain unknown, although the discovery that it can have a genetic basis in mice represents an important step towards the understanding of its pathogenesis. Sirenomelia occurs in mice lacking Cyp26a1, an enzyme that degrades retinoic acid (RA), and in mice that develop with reduced bone morphogenetic protein (Bmp) signaling in the caudal embryonic region.

Paper 6: EUROCAT member registries: organization and activities.

Background: EUROCAT is a network of population-based congenital anomaly registries providing standardized epidemiologic information on congenital anomalies in Europe. There are three types of EUROCAT membership: full, associate, or affiliate. Full member registries send individual records of all congenital anomalies covered by their region.

Prevention, diagnosis and services.

This chapter summarizes how prevention, diagnosis and services can result from the activities of a research programme on the group of rare diseases constituted by congenital anomalies. The Spanish Collaborative Study of Congenital Malformations (ECEMC) is a research programme based on a case-control registry of consecutive newborn infants with congenital anomalies. Its aim is the prevention of this group of rare diseases, through the research on their causes and pathogenesis, combined with the translational activity to transfer the benefits of this knowledge to the general population and health care providers.

Four small supernumerary marker chromosomes derived from chromosomes 6, 8, 11 and 12 in a patient with minimal clinical abnormalities: a case report.

Introduction: Small supernumerary marker chromosomes are still a problem in cytogenetic diagnostic and genetic counseling. This holds especially true for the rare cases with multiple small supernumerary marker chromosomes. Most such cases are reported to be clinically severely affected due to the chromosomal imbalances induced by the presence of small supernumerary marker chromosomes.

Review of the recently defined molecular mechanisms underlying thanatophoric dysplasia and their potential therapeutic implications for achondroplasia.

Achondroplasia (ACH), thanatophoric dysplasia (TD) types I and II, hypochondroplasia (HCH), and severe achondroplasia with developmental delay and acanthosis nigricans (SADDAN) are all due to activating mutations in the fibroblast growth factor receptor 3 (FGFR3) gene. We review the clinical, epidemiological, radiological, molecular aspects, and signaling pathways involved in these conditions. It is known that FGFR3 signaling is essential to regulate bone growth.

Can our understanding of epigenetics assist with primary prevention of congenital defects?

Having identified teratogenic factors, primary prevention of congenital defects is possible by the implementation of specific measures in pregnant women or those planning pregnancy. Our current understanding of the epigenetic processes acting during reproductive events raises new possibilities to prevent both heritable and sporadic congenital anomalies. Cell differentiation during embryonic-fetal development involves different epigenetic processes which, if altered, may affect either somatic or germ cells.