Debunking Occam's razor: Diagnosing multiple genetic diseases in families by whole-exome sequencing.

BACKGROUND: Recent clinical whole exome sequencing (WES) cohorts have identified unanticipated multiple genetic diagnoses in single patients. However, the frequency of multiple genetic diagnoses in families is largely unknown. AIMS: We set out to identify the rate of multiple genetic diagnoses in probands and their families referred for analysis in two national research programs in Canada. MATERIALS & METHODS: We retrospectively analyzed WES results for 802 undiagnosed probands referred over the past 5 years in either the FORGE or Care4Rare Canada WES initiatives. RESULTS: Of the 802 probands, 226 (28.2%) were diagnosed based on mutations in known disease genes. Eight (3.5%) had two or more genetic diagnoses explaining their clinical phenotype, a rate in keeping with the large published studies (average 4.3%; 1.4 - 7.2%). Seven of the 8 probands had family members with one or more of the molecularly diagnosed diseases. Consanguinity and multisystem disease appeared to increase the likelihood of multiple genetic diagnoses in a family. CONCLUSION: Our findings highlight the importance of comprehensive clinical phenotyping of family members to ultimately provide accurate genetic counseling.

Compound heterozygous mutations in the IFT140 gene cause Opitz trigonocephaly C syndrome in a patient with typical features of a ciliopathy.

〈 We report on an infant with Opitz trigonocephaly C syndrome (OTCS), who also had manifestations of ciliopathy, including short ribs (non-asphyxiating), trident acetabular roofs, postaxial polydactyly cone-shaped epiphyses, and dysplasia of the renal, hepatic and pancreatic tissues. To investigate the molecular cause, we used an exome sequencing strategy followed by Sanger sequencing. Two rare variants, both predicted to result in loss of functional protein, were identified in the IFT140 gene; a substitution at the splice donor site of exon 24 (c.723 + 1 G > T) and a 17 bp deletion, impacting the first coding exon (c.-11_6del). The variants were confirmed as being biallelic using Sanger sequencing, showing that the splice variant was inherited from the propositus mother and the deletion from the father. To date, Mainzer-Saldino syndrome, Jeune syndrome, and a form of nonsyndromic retinal dystrophy, have been identified as ciliopathies caused by IFT140 mutations. We provide the first description of an OTCS phenotype that appears to result from IFT140 mutations. The presentation of this patient is consistent with previous reports showing that OTCS already exhibited skeleletal and nonskeletal features of a ciliopathy.

Mechanical strength vs. degradation of a biologically-derived surgical mesh over time in a rodent full thickness abdominal wall defect.

The use of synthetic surgical mesh materials has been shown to decrease the incidence of hernia recurrence, but can be associated with undesirable effects such as infection, chronic discomfort, and adhesion to viscera. Surgical meshes composed of extracellular matrix (i.e., biologically-derived mesh) are an alternative to synthetic meshes and can reduce some of these undesirable effects but are less frequently used due to greater cost and perceived inadequate strength as the mesh material degrades and is replaced by host tissue. The present study assessed the temporal association between mechanical properties and degradation of biologic mesh composed of urinary bladder matrix (UBM) in a rodent model of full thickness abdominal wall defect. Mesh degradation was evaluated for non-chemically crosslinked scaffolds with the use of (14)C-radiolabeled UBM. UBM biologic mesh was 50% degraded by 26 days and was completely degraded by 90 days. The mechanical properties of the UBM biologic mesh showed a rapid initial decrease in strength and modulus that was not proportionately associated with its degradation as measured by (14)C. The loss of strength and modulus was followed by a gradual increase in these values that was associated with the deposition of new, host derived connective tissue. The strength and modulus values were comparable to or greater than those of the native abdominal wall at all time points.

Utility of whole-exome sequencing for those near the end of the diagnostic odyssey: time to address gaps in care.

An accurate diagnosis is an integral component of patient care for children with rare genetic disease. Recent advances in sequencing, in particular whole-exome sequencing (WES), are identifying the genetic basis of disease for 25-40% of patients. The diagnostic rate is probably influenced by when in the diagnostic process WES is used. The Finding Of Rare Disease GEnes (FORGE) Canada project was a nation-wide effort to identify mutations for childhood-onset disorders using WES. Most children enrolled in the FORGE project were toward the end of the diagnostic odyssey. The two primary outcomes of FORGE were novel gene discovery and the identification of mutations in genes known to cause disease. In the latter instance, WES identified mutations in known disease genes for 105 of 362 families studied (29%), thereby informing the impact of WES in the setting of the diagnostic odyssey. Our analysis of this dataset showed that these known disease genes were not identified prior to WES enrollment for two key reasons: genetic heterogeneity associated with a clinical diagnosis and atypical presentation of known, clinically recognized diseases. What is becoming increasingly clear is that WES will be paradigm altering for patients and families with rare genetic diseases.

Buschke-Ollendorff syndrome: a novel case series and systematic review.

Buschke-Ollendorff syndrome (BOS) is a rare, often benign, autosomal skin disorder. BOS commonly presents with nontender connective tissue naevi and sclerotic bony lesions (osteopoikilosis [OPK]). Herein, we summarize the presenting features of BOS and potential associations by conducting a systematic review of the literature and summarizing a cohort seen at the Hospital for Sick Children (HSC), Toronto, Canada. PubMed was searched using the following terms: 'BOS'; 'dermatofibrosis lenticularis'; 'OPK'; 'LEMD3'; 'elastoma'; 'collagenoma'. Only case reports were included, without date or language restrictions. Cases were further narrowed to those where patients or their families had a combination of skin and bony lesions, or a positive genetic test. Data were summarized using frequencies. In total, 594 reports were discovered, of which 546 (92%) were excluded. The remaining 48 accounted for 164 cases. Skin lesions were noted in 24% of cases and bony lesions in 20%, while 54% of patients had both. In 1% of cases the diagnosis was made on genetic testing alone. A family history was noted in 92% of cases. All patients with spinal stenosis (2%) or shortened status (7%) had OPK. Six per cent of patients had neurological problems. However, 50% of the cohort from HSC had cognitive delays, and only cases from 2007 onwards reported cognitive delays (the prevalence was 17% among those cases). This review confirms the classical diagnostic features of BOS. In addition, it highlights a previously unreported association between a shortened stature and OPK, as well as a possible association with cognitive delays.

NSD1 mutations generate a genome-wide DNA methylation signature.

Sotos syndrome (SS) represents an important human model system for the study of epigenetic regulation; it is an overgrowth/intellectual disability syndrome caused by mutations in a histone methyltransferase, NSD1. As layered epigenetic modifications are often interdependent, we propose that pathogenic NSD1 mutations have a genome-wide impact on the most stable epigenetic mark, DNA methylation (DNAm). By interrogating DNAm in SS patients, we identify a genome-wide, highly significant NSD1(+/-)-specific signature that differentiates pathogenic NSD1 mutations from controls, benign NSD1 variants and the clinically overlapping Weaver syndrome. Validation studies of independent cohorts of SS and controls assigned 100% of these samples correctly. This highly specific and sensitive NSD1(+/-) signature encompasses genes that function in cellular morphogenesis and neuronal differentiation, reflecting cardinal features of the SS phenotype. The identification of SS-specific genome-wide DNAm alterations will facilitate both the elucidation of the molecular pathophysiology of SS and the development of improved diagnostic testing.

Parámetros fisiológicos y valores hematológicos normales en búfalos (Bubalus bubalis) del Magdalena Medio colombiano / Normal Physiological Parameters and Hematological Values in Water Buffalos (Bubalus bubalis) from the Colombian Middle Magdalena

El presente estudio se realizó en 171 animales de la hacienda La Suiza, ubicada en el municipiode Puerto Nare, Antioquia, con el fin de determinar los parámetros fisiológicos y valores hematológicos en búfalos de agua (Bubalus bubalis) del Magdalena Medio colombiano. Esta población fue seleccionada y catalogada en diferentes grupos de edades, así: menores de un año, 51 animales; de uno a tres años, 56 animales, y mayores de tres años, 64 animales. Se tomaron las frecuencias cardiaca, respiratoria, pulso, tiempo de llenado capilar, movimientos ruminales y temperatura a los mismos animales una vez al mes durante cuatro meses. Asi mismo,se les extrajo sangre de la vena yugular para análisis hematológico de hematocrito, proteínas plasmáticas totales, proteínas séricas totales y recuento leucocitario. Resultados: se encontraron rangos de referencia de parámetros fisiológicos y hematológicos en búfalos de agua de la hacienda La Suiza, en el Magdalena Medio colombiano...

This study was conducted with 171 animals from La Suiza Farm, located in the Municipalityof Puerto Nare, Antioquia, in order to determine the physiological parameters and hematologicalvalues in water buffalos (Bubalus bubalis) from the Colombian Middle Magdalena.This population was selected and classified into different age groups as follows: under oneyear of age, 51 animals; one to three years of age: 56 animals, and over three years of age: 64animals. Heart rate, breathing rate, pulse, capillary refill time, temperature and rumian movementswere taken from the same animals once a month for 4 months. Likewise, blood wasextracted from the jugular vein for hematologic analysis of hematocrit, total plasma protein,total serum protein and leukocyte count. Results: reference ranges of physiological and hematologicalparameters were found in water buffalos from La Suiza Farm in the ColombianMiddle Magdalena...

O presente estudo realizou-se em 171 animais da fazenda La Suiza, localizada no municípiode Puerto Nare, Antioquia, com o objetivo de determinar os parâmetros fisiológicos e valoreshematológicos em búfalos de água (Bubalus bubalis) do Magdalena Médio colombiano.Esta população foi selecionada e catalogada em diferentes grupos de idade, da seguinteforma: menores de um ano, 51 animais; de um a três anos, 56 animais, e maiores de trêsanos, 64 animais. Foram medias as frequências cardíacas, respiratória, pulso, tempo de preenchimentocapilar, movimentos ruminais e temperatura aos mesmos animais uma vez pormês, durante quatro meses. Da mesma forma, extraiu-se sangue da veia jugular para análisehematológica de hematócrito, proteínas plasmáticas totais, proteínas soro totais e recontagemde leucócitos. Resultados: foi encontrado faixas de referência de parâmetros fisiológicose hematológicos em búfalos de água da fazenda La Suiza, no Magdalena Médio colombiano...

Aplasia of cochlear nerves and olfactory bulbs in association with SOX10 mutation.

A 17-month-old boy was referred with profound sensorineural hearing loss (SNHL), severe visual impairment and developmental delay. Neuroimaging identified hypomyelination and cochlear nerve aplasia. He was noted to have fair skin and hair and multiple areas of cutaneous hyperpigmentation. Previous investigations including karyotype, array comparative genomic hybridization (aCGH) and a full metabolic screen were normal. A novel missense mutation of the highly conserved high mobility group (HMG) domain of SOX10 was identified (Q174P:c.521A>C). This case represents the first description of aplasia of the cochlear nerve due to a SOX10 mutation.

Molecular and clinical characterization of de novo and familial cases with microduplication 3q29: guidelines for copy number variation case reporting.

Microdeletions of 3q29 have previously been reported, but the postulated reciprocal microduplication has only recently been observed. Here, cases from four families, two ascertained in Toronto (Canada) and one each from Edinburgh (UK) and Leiden (Netherlands), carrying microduplications of 3q29 are presented. These families have been characterized by cytogenetic and molecular techniques, and all individuals have been further characterized with genome-wide, high density single nucleotide polymorphism (SNP) arrays run at a single centre (The Centre for Applied Genomics, Toronto). In addition to polymorphic copy-number variants (CNV), all carry duplications of 3q29 ranging in size from 1.9 to 2.4 Mb, encompassing multiple genes and defining a minimum region of overlap of about 1.6 Mb bounded by clusters of segmental duplications that is remarkably similar in location to previously reported 3q29 microdeletions. Consistent with other reports, the phenotype is variable, although developmental delay and significant ophthalmological findings were recurrent, suggesting that dosage sensitivity of genes located within 3q29 is important for eye and CNS development. We also consider CNVs found elsewhere in the genome for their contribution to the phenotype. We conclude by providing preliminary guidelines for management and anticipatory care of families with this microduplication, thereby establishing a standard for CNV reporting.

Artroplastia de Swanson de la Articulación Metacarpofalángica en Artritis Reumatoidea: revisión del tema / Swanson Arthroplasty of metacarpophalangeal en la Articulación Reumatoidea Arthritis: revisión del theme

Las manos son fundamentales en las actividades laborales y de la vida diaria, hacen parte del lenguaje e identidad corporal y cualquier afección desencadena trastornos funcionales y psicosociales. La artritis reumatoidea compromete la articulación metacarpofalángica, clave de la mano en su función y la artroplastia de Swanson ha sido un gran avance y tratamiento de elección de las deformidades sintomáticas por 40 años. Funciona sin fijación como espaciador mediante encapsulamiento, que permite un arco de movimiento funcional. Se indica en los estadios 3(tardío), 4(muy tardío), de deformidades reumáticas o postraumáticas que presentan dolor o compromiso cosmético que afecte la imagen corporal. Para realizarla, se evalúa el estado y deformidad de otras articulaciones para corregirlas previamente si se encuentra indicado. Por la resección ósea limitada y preservación de tejidos blandos, esta artroplastia permite cirugías reconstructivas secundarias. Se describe la técnica quirúrgica, manejo postoperatorio, complicaciones y resultados obtenidos en diferentes series aparecidas en la literatura.

Omphalocele in trisomy 3q: further delineation of phenotype.

We report a case of a patient with omphalocele, dysmorphic features, and mild developmental delay associated with a chromosomal aberration. Chromosome studies showed that the propositus carries a maternally derived unbalanced translocation der(4)t(3;4)(q27.3;q32.3), resulting in trisomy for region 3q27.3-->qter and monosomy for 4q32.3-->qter. Because the association between dup3q and omphalocele has been reported in several cases, we analyzed the data on 93 previously reported patients with partial trisomy of the long arm of chromosome 3 and compared the clinical features between the cases. The imbalance of chromosome 3 in the patient was further defined by fluorescence in situ hybridization (FISH) studies using bacterial artificial chromosome (BAC) clones. BAC clone RP11-171N2 was identified as a breakpoint-spanning clone in the patient and his mother. Based on our comparative analysis, we have delineated that the smallest region of overlap (SRO) associated with omphalocele is from BAC 171N2 to 3qter. We hypothesize that the SRO contains a gene(s) important in normal abdominal wall development and is of potential interest for further investigation.

A Colombian family with X-linked juvenile retinoschisis with three affected females finding of a frameshift mutation.

X-linked retinoschisis (XLRS) is a vitreoretinal disease responsible for most cases of juvenile macular degeneration in males. Retinoschisis carrier females generally manifest no pathological symptoms. However, a large affected family from Colombia presented three affected females with typical RS phenotype similar to their 27 affected male relatives. Fundus examination as well as electroretinograms (ERG) indicate that the disease in these three affected females is as severe as in their affected male counterparts. DNA sequence analysis of the XLRS1 gene in the affected members of this family indicates a single base (G) deletion at the 639 base position (639delG). This deletion causes a frameshift during translation and results in a larger (235 amino acids) than normal peptide (224 amino acids) with grossly altered discoidin domain, which is considered critical for the cellular function of the protein. The co-segregation of this gene mutation with the RS phenotype and the RS carrier status as well as its complete absence in normal controls indicates that this genetic change is responsible for the RS pathology in this family. This (639delG) is a novel RS mutation and reported here for the first time. Furthermore, the analysis of the three affected females indicates that the RS pathology in affected females (a very rare occurrence) is due to XLRS1 mutations carried on both of their X chromosomes.

Comportamiento clínico de un cemento biocompatible en la técnica endodóntica convencional con base en hidróxido de calcio / Clinical behavior of a biocompatible root canal sealer in the conventional endodontic technique based on calcium hydroxide

Existe una gran cantidad de referencias en la literatura odontológica acerca de los usos y efectos del hidróxido de calcio, sobre todo, aplicado a las técnicas endodónticas. En el estudio que presentamos, se usó en 105 casos clínicos, con base en el supuesto demostrado por otros acerca de su efecto biocompatible en el tratamiento de algunas patologías de origen endodóntico. Leonardo M.R., preconizó su uso como tapón apical previo a la endodoncia definitiva, en los casos llamados por él como "biopulpectomía". En esta investigación se generalizó su uso para todos los casos de dientes maduros que requerían endodoncia, en los cuales independientemente del diagnóstico, se obtuvo un éxito significativo (93,4 por ciento), mejorando las características del cemento, lo cual permite recomendarlo en la técnica endodóntica rutinaria agregado como elemento sellador

Clinical and laboratory studies with amikacin in newborns, infants, and children.

Thirty (86%) of 35 infants and older children with proven gram-negative sepsis had a complete clinical remission after treatment with amikacin. In 27 (82%) of 33 infectious episodes for which bacteriologic results were available before and after treatment, the organism was eradicated. The dosage of amikacin was either 7.5 mg/kg or 15 mg/kg given intramuscularly at 12-hr intervals. No adverse clinical effects or laboratory abnormalities were observed during treatment, which lasted from five to 14 days. All bacteria were sensitive to amikacin when tested by the disk diffusion method, and all but a single strain of Pseudomonas were sensitive when tested by the agar dilution method. Assays of serum and urine demonstrated adequate levels of amikacin after single intramuscular injections of 3.75 or 7.5 mg/kg; simultaneous assays of serum and cerebrospinal fluid in two cases demonstrated comparable concentrations of drug suggestive of a high degree of penetration into the cerebrospinal fluid in two cases demonstrated comparable concentrations of drug suggestive of a high degree of penetration into the cerebrospinal fluid during infection. Serial measurements of amikacin in serum from 0.5 to 12 hr after administration of single doses of 7.5 mg of drug/kg to six newborns revealed no significant differences in the concentrations achieved with intramuscular or intravenous administration of the drug.