Bardet-Biedl Syndrome-Multiple Kaleidoscope Images: Insight into Mechanisms of Genotype-Phenotype Correlations.

Bardet-Biedl Syndrome is a rare non-motile primary ciliopathy with multisystem involvement and autosomal recessive inheritance. The clinical picture is extremely polymorphic. The main clinical features are retinal cone-rod dystrophy, central obesity, postaxial polydactyly, cognitive impairment, hypogonadism and genitourinary abnormalities, and kidney disease. It is caused by various types of mutations, mainly in genes encoding BBSome proteins, chaperonins, and IFT complex. Variable expressivity and pleiotropy are correlated with the existence of multiple genes and variants modifiers. This review is focused on the phenomena of heterogeneity (locus, allelic, mutational, and clinical) in Bardet-Biedl Syndrome, its mechanisms, and importance in early diagnosis and proper management.

Phenotypic Characterization of Immortalized Chondrocytes from a Desbuquois Dysplasia Type 1 Mouse Model: A Tool for Studying Defects in Glycosaminoglycan Biosynthesis.

The complexity of skeletal pathologies makes use of in vivo models essential to elucidate the pathogenesis of the diseases; nevertheless, chondrocyte and osteoblast cell lines provide relevant information on the underlying disease mechanisms. Due to the limitations of primary chondrocytes, immortalized cells represent a unique tool to overcome this problem since they grow very easily for several passages. However, in the immortalization procedure the cells might lose the original phenotype; thus, these cell lines should be deeply characterized before their use. We immortalized primary chondrocytes from a Cant1 knock-out mouse, an animal model of Desbuquois dysplasia type 1, with a plasmid expressing the SV40 large and small T antigen. This cell line, based on morphological and biochemical parameters, showed preservation of the chondrocyte phenotype. In addition reduced proteoglycan synthesis and oversulfation of glycosaminoglycan chains were demonstrated, as already observed in primary chondrocytes from the Cant1 knock-out mouse. In conclusion, immortalized Cant1 knock-out chondrocytes maintained the disease phenotype observed in primary cells validating the in vitro model and providing an additional tool to further study the proteoglycan biosynthesis defect. The same approach might be extended to other cartilage disorders.

A Stepwise Algorithmic Approach and External Validation Study for Noninvasive Prediction of Advanced Fibrosis in Nonalcoholic Fatty Liver Disease.

BACKGROUND AND AIMS: Advanced F3-4 fibrosis predicts liver-related mortality in nonalcoholic fatty liver disease (NAFLD). Noninvasive tests, designed to rule in/out advanced fibrosis, are limited by indeterminates, necessitating biopsy. We aimed to determine whether stepwise combinations of noninvasive serum-based tests and elastography (VCTE) could predict F3-4, reduce indeterminates, and decrease liver biopsies. METHODS AND RESULTS: Five hundred forty-one biopsy-proven NAFLD cases were identified between 2010 and 2018 from two Canadian centers. Characteristics of training (n = 407)/validation (n = 134) cohorts included: males 54%/59%; mean age 48.5/52.5 years; mean body mass index 32.3/33.6 kg/m2; diabetes mellitus 30%/34%; and F3-4 48%/43%. For training/validation cohorts, area under the receiver operating curve (AUROC) for FIB-4, AST-platelet ratio index (APRI), NAFLD fibrosis score (NFS), BARD score, and AST/ALT ratio ranged from 0.70 to 0.83/0.68 to 0.81, with indeterminates 25-39%/34-45%, for F3-4. In the training cohort, parallel FIB-4 + NFS had good accuracy (AUROC = 0.81) but was limited by 38% indeterminates and 16% misclassified. Sequential FIB-4 → NFS reduced indeterminates to 10%, and FIB-4 → VCTE to 0%, misclassified 20-22%, while maintaining high specificity (0.88-0.92) and accuracy (AUROC 0.75-0.78) for combined cohorts. Liver biopsy could have been avoided in 27-29% of patients using sequential algorithms. CONCLUSIONS: Sequential FIB-4 âž” NFS/VCTE predicts F3-4 with high specificity and good accuracy, while reducing indeterminates and need for biopsy. Parallel algorithms are limited by high indeterminates. Sequential FIB-4 âž” NFS had similar accuracy to VCTE-containing algorithms. Validation in low-prevalence cohorts may allow for potential use in community or resource-limited areas for risk stratification.

Bardet-Biedl 9 Syndrome, A Rare Mutation.

Bardet- biedl syndrome (BBS) is a rare heterogenous autosomal recessive disease due to defects in primary cilia which until now, up to 21 types have been detected. A few reports of BBS in Iran have been published but this is the first type 9 genotyped and clinically discussed case. This type can cause severe and delayed onset renal failure.

Empty sella associated with growth hormone deficiency and polydactyly.

Empty sella means the absence of the pituitary gland on cranial computed tomography or magnetic resonance imaging. Empty sella syndrome is the pathological variant of the imaging-described empty sella. We present the case of a male Caucasian child, aged four years and two months, for short stature and diagnosed by imaging procedures as empty sella. The cause of short stature was isolated growth hormone (GH) deficiency. Associated he presented left hand postaxial polydactyly. In connection with this particular case, we propose a review of current knowledge in empty sella syndrome. The particularity of reported case consists of association empty sella with GH deficiency and polydactyly. The association of empty sella with polydactyly is not reported yet in the medical literature and is probably coincidental.

Prehistoric polydactylism: Biological evidence and rock art representation from the Atacama Desert in northern Chile.

A review of the bioarchaeological collections from the site Morro de Arica in northern Chile allowed the identification of two cases of human polydactyly. Both cases are from the Chinchorro culture, hunters, fishers, and gatherers with a maritime orientation who inhabited the coast of the Atacama Desert (9000-3400 BP). Additionally, the analyses of 75 rock art sites in the area, from the Formative to Late Intermediate Periods (3000-550 BP), allowed the identification of hands and feet with six digits. Given the bioarchaeological record of polydactyly, it is highly probable that the rock art images were based on real individuals with polydactyly. However, the Sr chemical signal in a juvenile with polydactyly is the same as the Sr chemical signal in the rest of the individuals buried in the same site, proving that all the individuals were born and lived on the coast. We discuss the idea that, although these anomalies could have been the result of genetic mutations, endogamy and exposition to ecotoxic environments could also be at play within the Chinchorro groups.

The Dynamics of the Frequency of Polydactyly, Reduction Defects of Limbs and Multiple Congenital Malformations in Newborns of Radioactively Contaminated Areas of the Bryansk Region (1999-2014).

On the basis of official statistical data for 1999-2014 the authors assessed the frequency of polydactyly, reduction defects of limbs and multiple congenital malformations in newborns of the Bryansk region living in the areas with different densities of radioactive contamination by long-lived radionuclides cesium-137.(3.0 to 2523.4 kBq/m(2)) and strontium-90 (from 0.02 to 42.5 kBq/M(2)). The findings did not reveal statistically significant differences in the frequency of polydactyly, reduction defects of limbs and multiple congenital malformations in newborns in the South-Western Territories compared with medium-regional values, although the maximum value of the sum of congenital. developmental anomalies (polydactyly, reduction limb defects and multiple congenital malformations) are detected in the above-mentioned most contaminated areas.

Ellis van Creveld: reporte de caso / Ellis van Creveld: Case report

Introduction: Ellis-van Creveld (EVC) (OMIM # 225500) syndrome is a rare skeletal dysplasia disorder transmitted by autosomal recessive inheritance. The diagnosis is made based on phenotypic characteristics such as chondrodysplasia, heart defects and polydactyly. The prognosis depends mainly on the severity of the disease, diagnosis and comprehensive management of the condition. Objective: To describe a patient diagnosed with EVC syndrome. Case report: Newborn diagnosed with EVC syndrome who presented dysmorphic facies, shortened long bones, rhizomelic shortening, small hands, brachydactyly, single transverse palmar crease, postaxial polydactyly in the upper limbs, bilateral preaxial polysyndactyly in lower limbs and hypoplastic nails, complex heart defects and narrow thorax. The evolution was unfavorable; the patient died 8 weeks after birth from complications due to heart defects. Conclusions: EVC syndrome is rare and unknown; therefore, it is important to spread its characteristics within the pediatric community, emphasizing that it affects multiple organ systems and requires a multidisciplinary approach to treat individually each patient, to provide genetic and reproductive counseling to couples and to give information regarding child development expectations.

Introducción: El síndrome Ellis-van Creveld (EVC) (OMIM #225500) es una displasia esquelética rara de herencia autosómica recesiva, cuyo diagnóstico se realiza por sus características fenotípicas como la condrodisplasia, cardiopatía y polidactilia. El pronóstico depende fundamentalmente de la severidad de la cardiopatía, al igual que del diagnóstico y manejo integral oportunos. Objetivo: Caracterizar un paciente con diagnóstico clínico de Síndrome de EVC, cuya baja frecuencia dificulta el correcto diagnóstico en pediatría. Caso clínico: Recién nacido con facies dismórfica, extremidades con huesos largos cortos, acortamiento rizomélico, manos pequeñas, braquidactilia, pliegue palmar único, polidactilia post axial en miembros superiores, polisin-dactilia preaxial bilateral en miembros inferiores y uñas hipoplásicas, cardiopatía compleja y tórax estrecho, en el que se concluyó un diagnóstico clínico de EVC. La evolución fue desfavorable, falleciendo a las 8 semanas de nacimiento por complicaciones secundarias a la cardiopatía. Conclusiones: El síndrome de EVC es de baja frecuencia y poco conocido, por lo que es importante difundir sus características en la comunidad pediátrica, haciendo énfasis en que al afectar múltiples sistemas y órganos, requiere un manejo multidisciplinario con el objetivo de intervenir en la patología individualizando cada paciente; además de consejería genética y reproductiva a las parejas, e información de las expectativas del desarrollo del niño.

Vascular limb defects and maternal age.

BACKGROUND: The prenatal diagnosis procedure chorionic villus sampling is associated with increased risk of vascular disruption limb defects. Some studies have suggested that these defects are more common among infants born to women 35 years and older while other studies have shown a correlation with younger mothers. METHODS: All infants with vascular disruption defects were identified in the Active Malformations Surveillance Program at Brigham and Women's Hospital in the years 1972-1974, 1979-2011. We compared the rate of occurrence of infants with vascular limb defects among women in theses age groups: ≤19, 20 to 34, and ≥35 years to the rate of occurrence of infants with preaxial polydactyly, adjusting for race. Infants with an identifiable cause of their defects were excluded. RESULTS: 106 infants with vascular disruption defects and 67 with preaxial polydactyly were identified. Seventeen percent of the infants with vascular disruption defects and 25% of the infants with preaxial polydactyly were born to women 35 and older (p = 0.23). In contrast, 16% of the infants with vascular disruption defects were born to young mothers (≤19 years) compared with 6.0% of the mothers of infants with preaxial polydactyly (adjusted odds ratio vs. 35+ years = 5.3, 95% confidence interval 1.4-21, p = 0.017). CONCLUSION: Women 35 years old or older did not have increased risk for having a child with vascular disruption defects, but these defects were more common among infants of young (≤19) mothers, compared with the preaxial polydactyly group.

GATA6 is a crucial regulator of Shh in the limb bud.

In the limb bud, patterning along the anterior-posterior (A-P) axis is controlled by Sonic Hedgehog (Shh), a signaling molecule secreted by the "Zone of Polarizing Activity", an organizer tissue located in the posterior margin of the limb bud. We have found that the transcription factors GATA4 and GATA6, which are key regulators of cell identity, are expressed in an anterior to posterior gradient in the early limb bud, raising the possibility that GATA transcription factors may play an additional role in patterning this tissue. While both GATA4 and GATA6 are expressed in an A-P gradient in the forelimb buds, the hindlimb buds principally express GATA6 in an A-P gradient. Thus, to specifically examine the role of GATA6 in limb patterning we generated Prx1-Cre; GATA6(fl/fl) mice, which conditionally delete GATA6 from their developing limb buds. We found that these animals display ectopic expression of both Shh and its transcriptional targets specifically in the anterior mesenchyme of the hindlimb buds. Loss of GATA6 in the developing limbs results in the formation of preaxial polydactyly in the hindlimbs. Conversely, forced expression of GATA6 throughout the limb bud represses expression of Shh and results in hypomorphic limbs. We have found that GATA6 can bind to chromatin (isolated from limb buds) encoding either Shh or Gli1 regulatory elements that drive expression of these genes in this tissue, and demonstrated that GATA6 works synergistically with FOG co-factors to repress expression of luciferase reporters driven by these sequences. Most significantly, we have found that conditional loss of Shh in limb buds lacking GATA6 prevents development of hindlimb polydactyly in these compound mutant embryos, indicating that GATA6 expression in the anterior region of the limb bud blocks hindlimb polydactyly by repressing ectopic expression of Shh.

[Ellis van Creveld. Case report]. / Ellis van Creveld: reporte de caso.

INTRODUCTION: Ellis-van Creveld (EVC) (OMIM # 225500) syndrome is a rare skeletal dysplasia disorder transmitted by autosomal recessive inheritance. The diagnosis is made based on phenotypic characteristics such as chondrodysplasia, heart defects and polydactyly. The prognosis depends mainly on the severity of the disease, diagnosis and comprehensive management of the condition. OBJECTIVE: To describe a patient diagnosed with EVC syndrome. CASE REPORT: Newborn diagnosed with EVC syndrome who presented dysmorphic facies, shortened long bones, rhizomelic shortening, small hands, brachydactyly, single transverse palmar crease, postaxial polydactyly in the upper limbs, bilateral preaxial polysyndactyly in lower limbs and hypoplastic nails, complex heart defects and narrow thorax. The evolution was unfavorable; the patient died 8 weeks after birth from complications due to heart defects. CONCLUSIONS: EVC syndrome is rare and unknown; therefore, it is important to spread its characteristics within the pediatric community, emphasizing that it affects multiple organ systems and requires a multidisciplinary approach to treat individually each patient, to provide genetic and reproductive counseling to couples and to give information regarding child development expectations.

Effects of electromagnetic pulse on polydactyly of mouse fetuses.

There is an increasing public concern regarding potential health impacts from electromagnetic radiation exposure. Embryonic development is sensitive to the external environment, and limb development is vital for life quality. To determine the effects of electromagnetic pulse (EMP) on polydactyly of mouse fetuses, pregnant mice were sham-exposed or exposed to EMP (400 kV/m with 400 pulses) from Days 7 to 10 of pregnancy (Day 0 = day of detection of vaginal plug). As a positive control, mice were treated with 5-bromodeoxyuridine on Days 9 and 10. On Days 11 or 18, the fetuses were isolated. Compared with the sham-exposed group, the group exposed to EMP had increased rates of polydactyly fetuses (5.1% vs. 0.6%, P < 0.05) and abnormal gene expression (22.2% vs. 2.8%, P < 0.05). Ectopic expression of Fgf4 was detected in the apical ectodermal ridge, whereas overexpression and ectopic expression of Shh were detected in the zone of polarizing activity of limbs in the EMP-exposed group and in the positive control group. However, expression of Gli3 decreased in mesenchyme cells in those two groups. The percentages of programmed cell death of limbs in EMP-exposed and positive control group were decreased (3.57% and 2.94%, respectively, P < 0.05, compared with 7.76% in sham-exposed group). In conclusion, polydactyly induced by EMP was accompanied by abnormal expression of the above-mentioned genes and decreased percentage of programmed cell death during limb development.

Epidemiology of isolated preaxial polydactyly type I: data from the Polish Registry of Congenital Malformations (PRCM).

BACKGROUND: Polydactyly represents a heterogeneous group of congenital hand and foot anomalies with variable clinical features and diverse etiology. Preaxial polydactyly type I (PPD1) is the most frequent form of preaxial polydactyly. The etiology of sporadic PPD1 remains largely unknown and the relative contribution of genetic and environmental factors is not clearly defined. The primary goals of this study are twofold: (1) to examine the epidemiology and clinical features of sporadic PPD1 in comparison to a healthy control group, and (2) to contrast the characteristics of sporadic PPD1 with familial forms of isolated polydactyly. METHODS: Among 2,530,349 live births registered in the Polish Registry of Congenital Malformations (PRCM), we identified 459 children with isolated sporadic PPD1 and 353 children with familial polydactyly, including 57 children with familial PPD1. RESULTS: In comparison with the matched group of 303 controls, sporadic PPD1 cases had significantly lower birth order (P = 0.01) and birthweight (P < 0.0001). Similarly, when compared to familial cases of polydactyly, lower birth order (P = 0.047) and lower birthweight (P < 0.0001) were characteristic of sporadic PPD1 cases. Moreover, our analyses suggested several additional risk factors for sporadic PPD1, including lower paternal education levels (P = 0.01), upper respiratory tract infections during the first trimester of pregnancy (P = 0.049), and maternal history of epilepsy (P = 0.01). CONCLUSIONS: In summary, our study provides support to the hypothesis that non-genetic factors play an important role in the etiology of non-familiar PPD1.

Polidactilia: presentación de caso / Polidactilia. A case presentation

Paciente de sexo femenino de 23 años de edad que es matriculada en la Facultad de Medicina de Malanje, Angola que presenta un dedo supernumerario en la mano izquierda, localizado en el borde extremo del dedo pulgar, el mismo tiene movilidad propia y dos falanges. Es llevada al servicio de ortopedia del Hospital General de Malanje donde es examinada por el especialista y es indica una radiografía de la mano donde se confirma el diagnóstico de polidactilia pre axil tipo III. Se realizó la analítica preoperatoria, seguida de la amputación quirúrgica ambulatoria sin complicaciones(AU)

Diagnóstico clínico y molecular de síndrome de cefalopolisindactilia de Greig. A propósito de un caso. / Clinical and molecular cephalopolysyndactyly Greig syndrome. A case report

El síndrome de cefalopolisindactilia de Greig (SCPG) es una afección autosómica dominante caracterizada por polidactilia o sindactilia de manos y pies, macrocefalia, hipertelorismo y ocasionalmente anomalías cerebrales y retraso mental. Es un síndrome poco frecuente, heredado según un patrón autosómico dominante. La prevalencia es ignorada, siendo conocidos 100 casos aproximadamente. Más del 75 % de los pacientes con manifestaciones clínicas características de SCPG presentan mutaciones en el gen GLI3. El diagnóstico presuntivo de SCPG puede realizarse cuando el paciente presenta la tríada clásicade polidactilia, hipertelorismo y macrocefalia, siendo indicativo para la realización del análisis molecular del gen GLI3. En este trabajo se describe el caso de un niño referido al Instituto de Genética Médica con diagnóstico clínico de polidactilia y macrocefalia. Las características clínico-evolutivas e imagenológicas del paciente permitieron postular el diagnóstico de SCPG. El análisis molecular del gen GLI3 confirmó el diagnóstico de SCPG identificando la mutación c.1850_1852 del GTTinsAT (p.R617LfsX11) en el exón 12 del gen GLI3. Se trata de una mutación no descrita previamente como una mutación asociada al desarrollo de SCPG; no obstante, al tratarse de una mutación que provoca una proteína truncada desde el exón 12 del gen GLI3, no existen muchas dudas sobre su patogenicidad. Este resultado tiene implicaciones hereditarias y familiares permitiendo un adecuado asesoramiento genético en el contexto familiar.

Bardet-biedl syndrome in a child with chronic kidney disease.

A 4-year old boy was referred for evaluation of renal failure, posterior urethral valve (PUV) and urinary tract infection. His parents added complaints of polyuria, polydipsia, enuresis, shortness of stature, and inappropriate obesity. Serum blood urea nitrogen and creatinine levels were 45 and 3.5 mg/dL, respectively. Urine culture was positive for Pseudomonas aeruginosa, and abdominal ultrasound revealed bilateral small kidneys. The patient's history included mild to moderate mental retardation and postaxial polydactyly of both lower limbs amputated two years ago. The combination of mental retardation, obesity, postaxial polydactyly, and bilateral renal hypoplasia were compatible with the diagnosis Bardet-Biedl syndrome (BBS). The combination of PUV and BBS is a rare condition that caused this early onset of renal failure and inappropriate obesity guided us to the diagnosis.

[A case-control study on genetic and environmental factors regarding polydactyly and syndactyly].

OBJECTIVE: To explore the genetic and environmental factors related to the development of polydactyly and syndactyly, and to provide evidence for prevention on birth defects. METHODS: A hospital-based case-control study was conducted. 111 cases and 222 controls were interviewed with standardized questionnaires. Logistic regression models were used to select risk factors. RESULTS: Research data through univariate analysis showed that the occurrence of polydactyly and syndactyly were associated with educational level, annual average income per family member, meat and egg intake during early pregnancy, family heredity history, exposure to hazardous substance before pregnancy, serious pregnant reaction etc. of the pregnant women. As shown in multivariable logistic model, some factors, including annual average income of per family member (OR = 0.240), meat and egg intake during early pregnancy (OR = 0.182), could reduce the risk of the development of polydactyly and syndactyly. Other factors including family heredity history (OR = 10.187), exposure to hazardous substance before pregnancy (OR = 3.029), could increase the risk of developing polydactyly and syndactyly. The attributable risks (%) of family heredity history and exposure to hazardous substance before pregnancy were 90.18% and 66.99% respectively. CONCLUSION: Genetic factor was the leading cause on the development of polydactyly and syndactyly. In addition, environmental factors, such as family economic condition, nutritional status during early pregnancy and working condition before pregnancy were associated with the development of polydactyly and syndactyly.

Congenital panfollicular nevus associated with polydactyly.

A 2-year-old girl presented with ulnar-sided duplication of the left thumb distal to the interphalangeal joint and syndactyly of the first web space. She also had several asymptomatic pink-tan cutaneous papules, involving the first and second ray of the left hand and wrist, clinically resembling a linear epidermal nevus. Microscopically, the papules were composed of well-circumscribed aggregates of basaloid epithelium within the dermis. No normal hair follicles were identified. Follicular germ and papillae were identified, representing abortive attempts at hair follicle formation. The features were remarkably similar to a novel entity described by Finn and Argenyi as congenital panfollicular nevus. In our case, the congenital panfollicular nevus was associated with distal thumb polysyndactyly, which may suggest an important link between limb patterning and hair follicle development.