A large family with patent ductus arteriosus and unusual face

Crucial role of TFAP2B in the nervous system for regulating NREM sleep

The AP-2 transcription factors are crucial for regulating sleep in both vertebrate and invertebrate animals. In mice, loss of function of the transcription factor AP-2β (TFAP2B) reduces non-rapid eye movement (NREM) sleep. When and where TFAP2B functions, however, is unclear. Here, we used the Cre-loxP system to generate mice in which Tfap2b was specifically deleted in the nervous system during development and mice in which neuronal Tfap2b was specifically deleted postnatally. Both types of mice exhibited reduced NREM sleep, but the nervous system-specific deletion of Tfap2b resulted in more severe sleep phenotypes accompanied by defective light entrainment of the circadian clock and stereotypic jumping behavior. These findings indicate that TFAP2B in postnatal neurons functions at least partly in sleep regulation and imply that TFAP2B also functions either at earlier stages or in additional cell types within the nervous system.

Personalized Genetic Diagnosis of Congenital Heart Defects in Newborns

Congenital heart disease is a group of pathologies characterized by structural malformations of the heart or great vessels. These alterations occur during the embryonic period and are the most frequently observed severe congenital malformations, the main cause of neonatal mortality due to malformation, and the second most frequent congenital malformations overall after malformations of the central nervous system. The severity of different types of congenital heart disease varies depending on the combination of associated anatomical defects. The causes of these malformations are usually considered multifactorial, but genetic variants play a key role. Currently, use of high-throughput genetic technologies allows identification of pathogenic aneuploidies, deletions/duplications of large segments, as well as rare single nucleotide variants. The high incidence of congenital heart disease as well as the associated complications makes it necessary to establish a diagnosis as early as possible to adopt the most appropriate measures in a personalized approach. In this review, we provide an exhaustive update of the genetic bases of the most frequent congenital heart diseases as well as other syndromes associated with congenital heart defects, and how genetic data can be translated to clinical practice in a personalized approach.

Sleep Architecture in Mice Is Shaped by the Transcription Factor AP-2β

The molecular mechanism regulating sleep largely remains to be elucidated. In humans, families that carry mutations in TFAP2B, which encodes the transcription factor AP-2β, self-reported sleep abnormalities such as short-sleep and parasomnia. Notably, AP-2 transcription factors play essential roles in sleep regulation in the nematode Caenorhabditis elegans and the fruit fly Drosophila melanogaster Thus, AP-2 transcription factors might have a conserved role in sleep regulation across the animal phyla. However, direct evidence supporting the involvement of TFAP2B in mammalian sleep was lacking. In this study, by using the CRISPR/Cas9 technology, we generated two Tfap2b mutant mouse strains, Tfap2bK144 and Tfap2bK145 , each harboring a single-nucleotide mutation within the introns of Tfap2b mimicking the mutations in two human kindreds that self-reported sleep abnormalities. The effects of these mutations were compared with those of a Tfap2b knockout allele (Tfap2b-). The protein expression level of TFAP2B in the embryonic brain was reduced to about half in Tfap2b+/- mice and was further reduced in Tfap2b-/- mice. By contrast, the protein expression level was normal in Tfap2bK145/+ mice but was reduced in Tfap2bK145/K145 mice to a similar extent as Tfap2b-/- mice. Tfap2bK144/+ and Tfap2bK144/K144 showed normal protein expression levels. Tfap2b+/- female mice showed increased wakefulness time and decreased nonrapid eye movement sleep (NREMS) time. By contrast, Tfap2bK145/+ female mice showed an apparently normal amount of sleep but instead exhibited fragmented NREMS, whereas Tfap2bK144/+ male mice showed reduced NREMS time specifically in the dark phase. Finally, in the adult brain, Tfap2b-LacZ expression was detected in the superior colliculus, locus coeruleus, cerebellum, and the nucleus of solitary tract. These findings provide direct evidence that TFAP2B influences NREMS amounts in mice and also show that different mutations in Tfap2b can lead to diverse effects on sleep architecture.

Char Syndrome a novel mutation and new insights: A clinical report

Transcription Factor AP-2 Beta (TFAP2B) functions in the differentiation of neural crest cell derivatives and contributes to the embryogenesis of the ductus arteriosus. Mutations of TFAP2B produces Char syndrome. Char syndrome is an autosomal dominant disorder comprising facial dysmorphism, hand anomalies, and patent ductus arteriosus (PDA). In this report, we describe a proband with a de novo TFAP2B frameshift mutation c.650delG p.(Gly217Alafs*32) in the basic domain. The proband presented mainly with musculoskeletal features of Char syndrome. No PDA was identified at presentation suggesting that this syndrome may prove to be phenotypically heterogeneous. This report will help illustrate the genotype/phenotype correlation of TAFB2 mutations and better delineate the clinical features in Char syndrome.

Case report of a 26 year old primigravida with patent ductus arteriosus (PDA) in heart failure

Congenital heart disease is an important cause of maternal morbidity and mortality during pregnancy. Pregnancy alters the circulatory and respiratory physiology with attendant deleterious effect on the mother with congenital heart disease and the foetus. Additional insult to the circulatory physiology by other factors coexisting together with congenital heart disease can further reduce the cardiac reserve in pregnancy and precipitate heart failure. These factors include anaemia, thromboembolism, hypertension, multiple pregnancy, strenuous physical activity, extremes of temperature and the normal physiological edema of pregnancy.Patent ductus arteriosus (PDA) can present for the first time in pregnancy. Moderate to large PDA result in significant volume overload, left ventricular dilation and dysfunction. In the woman with a hemodynamically important PDA, pregnancy may precipitate or worsen heart failure. We report a successful pregnancy in a 26 year old primigravida with previously undetected patent ductus arteriosus with preeclampsia who presented in heart failure. This case highlights the importance of intensive careful examination of pregnant patients to identify such conditions.

Absent lacrimal ducts, distichiasis, dysmorphic features, and brachydactyly: a case report

We report a male patient presenting with the association of absent lacrimal ducts, distichiasis, dysmorphic facial features and limb abnormalities. Extensive chromosomal studies showed normal chromosomes. We discuss differential diagnoses such as Setleis, Char and Lacrimo-Auriculo-Dento-Digital (LADD) syndromes. This may represent a novel entity for which parental consanguinity would support an autosomal recessive mode of inheritance.

Char syndrome: an additional family with polythelia, a new finding

This report describes a father and daughter with Char syndrome, a rare autosomal dominant disorder. Both affected individuals had typical face, strabismus, and foot anomalies. The girl also had a patent ductus arteriosus. In addition, both patients had polythelia (supernumerary nipples), a finding not described before in the Char syndrome.

Mutations in TFAP2B cause Char syndrome, a familial form of patent ductus arteriosus

Char syndrome is an autosomal dominant trait characterized by patent ductus arteriosus, facial dysmorphism and hand anomalies. Using a positional candidacy strategy, we mapped TFAP2B, encoding a transcription factor expressed in neural crest cells, to the Char syndrome critical region and identified missense mutations altering conserved residues in two affected families. Mutant TFAP2B proteins dimerized properly in vitro, but showed abnormal binding to TFAP2 target sequence. Dimerization of both mutants with normal TFAP2B adversely affected transactivation, demonstrating a dominant-negative mechanism. Our work shows that TFAP2B has a role in ductal, facial and limb development and suggests that Char syndrome results from derangement of neural-crest-cell derivatives.

Familial patent ductus arteriosus and bicuspid aortic valve with hand anomalies: a novel heart-hand syndrome

The association between cardiac and limb defects, particularly those affecting the hand, has been well documented by the delineation of several heart-hand syndromes. Based on observations with a three-generation family with seven affected individuals, we describe a novel heart-hand syndrome comprising patent ductus arteriosus, bicuspid aortic valve, 5th metacarpal hypoplasia, and brachydactyly. The inheritance pattern was consistent with autosomal dominance, although X-linked dominance could not be excluded. Penetrance appeared to be complete, but there was variability of the cardiac and hand phenotypes. Because this new syndrome closely resembled Char syndrome (patent ductus arteriosus, 5th finger middle phalangeal hypoplasia, and minor facial anomalies), multipoint linkage analysis was performed using polymorphic DNA markers spanning the recently identified Char syndrome critical region at chromosomal bands 6p12-p21.1. This analysis formally excluded this 3-cM region, documenting that the two traits are not allelic. In sum, a novel heart-hand syndrome involving left ventricular outflow and aortic arch as well as an ulnar ray derivative has been identified. Because the hand anomalies can be subtle, thorough evaluation is suggested for families inheriting these cardiac defects as a mendelian trait.

Char syndrome, an inherited disorder with patent ductus arteriosus, maps to chromosome 6p12-p21

BACKGROUND

Patent ductus arteriosus (PDA) is a relatively common form of congenital heart disease. Although polygenic inheritance has been implicated, no specific gene defects causing PDA have been identified to date. Thus, a positional cloning strategy was undertaken to determine the gene responsible for the Char syndrome, an autosomal dominant disorder characterized by PDA, facial dysmorphism, and hand anomalies.

METHODS AND RESULTS

A genome scan was performed with 46 members of 2 unrelated families in which the disease was fully penetrant but the phenotype differed. Significant linkage was achieved with several polymorphic DNA markers mapping to chromosome 6p12-p21 (maximal 2-point LOD score of 8.39 with D6S1638 at theta=0.00). Haplotype analysis identified recombinant events that defined the Char syndrome locus with high probability to a 3. 1-cM region between D6S459/D6S1632/D6S1541 and D6S1024.

CONCLUSIONS

A familial syndrome in which PDA is a common feature was mapped to a narrow region of chromosome 6p12-p21. Additional analysis with other families and polymorphic markers as well as evaluation of potential candidate genes should lead to the identification of the Char syndrome gene, which will provide insights into cardiogenesis as well as limb and craniofacial development.

Familial occurrence of patent ductus arteriosus

We describe 7 relatives with patent ductus arteriosus (PDA) and a slightly unusual facial appearance with prominent midface with nose elongation and flattening of the nasal bridge, wide-set eyes, downturned palpebral fissures, mild ptosis, thickened lips, and apparently slightly low-set ears. Autosomal dominant inheritance is suggested in this family. Other families where affected members have PDA and a similar facial appearance and autosomal dominant inheritance were described previously by Char [1978: BD:OAS XIV (6B):303-305] and Temple [1992: Clin Dysmorphol 1:17-21].

Molecular basis of the common electrophoretic polymorphism (Fu1/Fu2) in human alpha-L-fucosidase

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