Analysis of COL1A1 and COL1A2 gene variants in two fetuses with osteogenesis imperfecta / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis of two fetuses with an osteogenesis imperfecta (OI) phenotype.@*METHODS@#Two fetuses diagnosed at the Affiliated Hospital of Weifang Medical College respectively on June 11, 2021 and October 16, 2021 were selected as the study subjects. Clinical data of the fetuses were collected. Amniotic fluid samples of the fetuses and peripheral blood samples of their pedigree members were collected for the extraction of genomic DNA. Whole exome sequencing (WES) and Sanger sequencing were carried out to identify the candidate variants. Minigene splicing reporter analysis was used to validate the variant which may affect the pre-mRNA splicing.@*RESULTS@#For fetus 1, ultrasonography at 17+6 weeks of gestation had revealed shortening of bilateral humerus and femurs by more than two weeks, in addition with multiple fractures and angular deformities of long bones. WES revealed that fetus 1 had harbored a heterozygous c.3949_3950insGGCATGT (p.N1317Rfs*114) variant in exon 49 of the COL1A1 gene (NM_000088.4). Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), it was classified as a pathogenic variant (PVS1+PS2+PM2_Supporting) for disrupting the downstream open reading frame resulting in premature translational termination, being de novo in origin, and lacking records in the population and disease databases.For fetus 2, ultrasonography at 23 weeks of gestation also revealed shortening of bilateral humerus and femurs by one and four weeks, respectively, in addition with bending of bilateral femurs, tibias and fibulas. Fetus 2 had harbored a heterozygous c.1557+3A>G variant in intron 26 of the COL1A2 gene (NM_000089.4). Minigene experiment showed that it has induced skipping of exon 26 from the COL1A2 mRNA transcript, resulting in an in-frame deletion (c.1504_1557del) of the COL1A2 mRNA transcript. The variant was inherited from its father and had been previously reported in a family with OI type 4. It was therefore classified as a pathogenic variant (PS3+PM1+PM2_Supporting+PP3+PP5).@*CONCLUSION@#The c.3949_3950insGGCATGT (p.N1317Rfs*114) variant in the COL1A1 gene and c.1557+3A>G variant in the COL1A2 gene probably underlay the disease in the two fetuses. Above findings not only have enriched the mutational spectrum of OI, but also shed light on the correlation between its genotype and phenotype and provided a basis for genetic counseling and prenatal diagnosis for the affected pedigrees.

Analysis of LRP5 gene variants in a Chinese pedigree affected with Osteoporosis-pseudoglioma syndrome / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis for a Chinese pedigree with two individuals suffering from congenital blindness.@*METHODS@#Clinical data and peripheral blood samples of the pedigree were collected. Whole exome sequencing was carried out. Suspected variants were verified by Sanger sequencing. Pathogenicity of candidate variants was validated through searching of PubMed and related databases, and analyzed with bioinformatics software.@*RESULTS@#Both patients had congenital blindness and a history of multiple fractures. Other features have included microphthalmia and cornea opacity. One patient had normal intelligence, whilst the other had a language deficit. Both patients were found to harbor compound heterozygous variants of the LRP5 gene, namely c.1007_1015delGTAAGGCAG (p.C336X), c.4400G>A (p.R1467Q) and c.4600C>T (p.R1534X). The first one was derived from their mother, whilst the latter two were derived from their father. None of the three variants was detected in their elder sister.@*CONCLUSION@#The compound heterozygous variants of c.1007_1015delGTAAGGCAG (p.C336X) and c.4600C>T (p.R1534X) of the LRP5 gene probably underlay the pathogenesis of the Osteoporosis-pseudoglioma syndrome in this pedigree. The clinical significance of the c.4400G>A (p.R1467Q) variant has remained uncertain. Above finding has enriched the mutational spectrum of Osteoporosis-pseudoglioma syndrome.

Identification of pathogenic variant and preimplantation genetic testing for a Chinese family affected with osteogenesis imperfecta / 中华医学遗传学杂志

OBJECTIVE@#To identify the pathogenic variant for a husband with osteogenesis imperfecta and provide preimplantation genetic testing (PGT) for the couple.@*METHODS@#High-throughput sequencing and Sanger sequencing were carried out to identify the pathologic variant in the husband patients. PGT of embryos was performed through direct detection of the mutation site. Meanwhile, chromosome aneuploidy of the blastocysts was screened. Following transplantation, cytogenetic and genetic testing of fetal amniotic fluid sample was carried out during mid-pregnancy. Chromosome copy number variant (CNV) was detected at multiple sites of the placenta after delivery.@*RESULTS@#The husband was found to harbor heterozygous c.544-2A>G variant of the COL1A1 gene. The same variant was not detected in either of his parents. PGT revealed that out of three embryos of the couple, one was wild-type for the c.544-2A site but mosaicism for duplication of 16p13.3.11.2. The other two embryos were both heterozygous for the c.544-2A>G variant. Following adequate genetic counseling, the wild-type embryo was transplanted. Amniotic fluid testing confirmed that the fetus had normal chromosomes and did not carry the c.544-2A>G variant. The copy number of chromosomes at different parts of placenta was normal after birth.@*CONCLUSION@#For couples affected with monogenic disorders, e.g., osteogenesis imperfecta, direct detection of the mutation site may be used for PGT after identifying the pathogenic variant. After adequate genetic counseling, prenatal diagnosis must be carried out to ensure the result.

Repetitive stress fracture: a warning sign of genetic susceptibility to fracture? A case report of a heterozygous variant in SERPINF1

SUMMARY The occurrence of fractures in young individuals is frequently overlooked by physicians, especially when associated with exercise or trauma. Nevertheless, multiple fractures should always be investigated since underlying conditions can predispose to such events. We describe here the case of a young, healthy woman who sustained multiple fractures in the lower limbs, which were initially considered to be "stress fractures". Further investigation, including a panel of genes associated with osteogenesis imperfecta, revealed that the patient is a heterozygous carrier of a SERPINF1 variant. According to criteria recommended by the American College of Medical Genetics and Genomics and the Association for Molecular Pathology, this variant is classified as likely benign (PM2, PP3, PP4, BP1, and BP4). The patient's mother and brother were also asymptomatic carriers of the variant and had sustained previous minor fractures. The patient had normal biochemical profile and bone density. This condition has been rarely described and is not associated with low bone mineral density or altered bone turnover markers. This case highlights the importance of investigating multiple fractures in young patients who are otherwise healthy since these may be a warning sign of rare genetic conditions associated with fragility fractures.

Preimplantation genetic testing for a couple where the husband is affected by osteogenesis imperfecta combined with balanced translocation using karyomapping technique / 中华医学遗传学杂志

OBJECTIVE@#To carry out preimplantation genetic testing (PGT) for a couple where the husband was affected by osteogenesis imperfecta combined with balanced translocation using the karyomapping technique.@*METHODS@#Blastocysts were detected using karyomapping, the carrier status of COL1A1 c.760G>A (p.Gly254Arg) variant and the carrier status of the translocated chromosome were analyzed simultaneously.@*RESULTS@#For a total of 10 blastocysts, two euploid blastocysts were found to not carry the COL1A1 c.760G>A (p.Gly254Arg) variant but a balanced translocation. After transplanting one of the blastocysts, clinical pregnancy was achieved. Amniocentesis at 18th gestational week and prenatal genetic testing was in keeping with the result of PGT.A healthy female was born at 40+4 weeks gestation.@*CONCLUSION@#For patients simultaneously carrying genetic variant and balanced chromosomal translocation, PGT can be performed with efficiency by the use of karyomapping method.

Osteogénesis imperfecta: hallazgos clínicos y epidemiológicos en una serie de pacientes pediátricos / Osteogenesis imperfect: clinical and epidemiological findings in a series of pediatric patients

Resumen Introducción: La osteogénesis imperfecta (OI) es el trastorno óseo hereditario más común, con una incidencia de 1 en 10,000 a 25,000 nacimientos. Este trastorno está causado principalmente por mutaciones de los genes que codifican las cadenas del colágeno tipo I. En la mayoría de los casos, se presenta un patrón de herencia autosómico dominante. La OI se caracteriza principalmente por un aumento en la fragilidad ósea que da lugar a fracturas frecuentes que producen dolor, deformidad y discapacidad asociada con otras alteraciones. El objetivo del estudio fue exponer las características clínicas y epidemiológicas de una serie de pacientes pediátricos con diagnóstico de OI evaluados en la Universidad de Los Andes. Métodos: El presente trabajo consiste en el análisis de una serie de 37 casos pediátricos con diagnóstico de OI, de acuerdo a la clasificación clínica y radiológica de Sillence, evaluados en la consulta de la Unidad de Genética Médica de la Universidad de Los Andes, entre enero de 2006 y diciembre de 2018. Resultados: La OI tipo I fue la de presentación más frecuente, con 31 pacientes (83.78%). El fémur fue el hueso más afectado de manera conjunta. Las escleras azules fueron el hallazgo adicional más frecuente, en 32 pacientes (86.49%). Conclusiones: La OI representa el principal motivo de consulta por alteraciones en el sistema esquelético en la Unidad de Genética Médica de la Universidad de Los Andes. Ante la amplia forma clínica de presentación, la evaluación debe ser individual e interdisciplinaria. A través de un estudio más profundo se podrá brindar el oportuno asesoramiento genético familiar.

Abstract Background: Osteogenesis imperfecta (OI) is the most common hereditary bone disorder with an incidence of one in 10,000-25,000 births. It is caused mainly by mutations in the genes that code for Type I collagen chains. In most cases, it shows an autosomal dominant inheritance pattern. OI is characterized by an increase in bone fragility that leads to frequent fractures, which cause pain, deformity and disability associated with other alterations. The objective of this study was to present the clinical and epidemiological characteristics of a series of pediatric patients diagnosed with OI evaluated at the University of Los Andes. Methods: A series of 37 pediatric cases with diagnosis of OI according to the clinical and radiological classification of sillence is analyzed, which were evaluated in the medical genetics unit of the University of Los Andes consultation between January 2006 and December 2018. Results: Type I was the most frequent OI type, with 31 patients (83.78%). Additionally, the femur was the most affected bone. Blue scleras were the most frequent additional finding in 32 patients (86.49%). Conclusions: OI represents the main reason for consultation of alterations in the skeletal system in the medical genetics unit of the University of Los Andes. Given the broad clinical presentation, the evaluation must be individual and interdisciplinary. Further study will provide timely family genetic counseling.

Osteogénesis Imperfecta. A propósito de un caso tipo II / Osteogenesis Imperfecta. About a type II case

RESUMEN El síndrome de Osteogénesis Imperfecta (OI) tipo II está dentro del grupo de trastornos del tejido conectivo de origen genético-hereditario que se caracteriza por fragilidad ósea, fracturas múltiples, huesos largos anchos y acortados, además de una pobre mineralización ósea. Su frecuencia de aparición se calcula en aproximadamente 1: 55.000 nacidos vivos y es el resultado de mutaciones de dos genes que codifican las cadenas de colágeno tipo 1. El riesgo de recurrencia es alrededor de 6 % pero si ambos padres fueran heterocigotos, aumentaría a 10-25 %. También se han reportado casos esporádicos por mutación de novo. El diagnóstico se suele realizar por los hallazgos ecográficos en el segundo trimestre o en ecografías previas si los hallazgos son muy evidentes. Las pruebas invasivas son útiles sobretodo en casos de antecedentes familiares con formas leves de OI. En nuestro caso, encontramos durante la ecografía de las 20 semanas una notable hipomineralización de la calota fetal sospechada por hiporrefringencia de la misma, acortamiento de extremidades superiores e inferiores con múltiples fracturas óseas, arcos costales cortos, arqueados y una desproporción toraco-abdominal. En los casos en donde se prosigue con el embarazo más de 60% de los recién nacidos mueren el primer día de vida, el resto lo hace durante el primer mes y la sobrevivencia más allá de un año es rara. La principal causa de muerte postnatal suele ser por falla respiratoria.

SUMMARY Osteogenesis Imperfecta (OI) type II is within the group of connective tissue disorders hereditary genetic-origin characterized by bone fragility, multiple fractures, broad long bones and shortened, and a poor bone mineralization. Their frequency is estimated at approximately 1: 55,000 live births, and is the result of mutations of genes which encoding chains of type 1 collagen. The risk of recurrence is around 6% but if both parents were heterozygous, increase to 10-25%. There has also been reported sporadic cases with de novo mutation. The diagnosis is usually made by ultrasound findings in second trimester or previously if the findings are very obvious. Invasive tests are useful especially in cases of family history with mild forms of OI. In our case, we found during ultrasound 20 weeks a remarkable hypomineralization of fetal calvarial, shortening of upper and lower extremities with multiple bone fractures and short costal arches, arched and thoracoabdominal disproportion. In cases where continued pregnancy more than 60% of newborns die during the first day of life, 80% die in the first month and survival beyond one year is rare. Death can occur prenatally or postnatamente from respiratory failure.

What is new in genetics and osteogenesis imperfecta classification? / O que há de novo em genética e classificação de osteogênese imperfeita?

OBJECTIVE: Literature review of new genes related to osteogenesis imperfecta (OI) and update of its classification. SOURCES: Literature review in the PubMed and OMIM databases, followed by selection of relevant references. SUMMARY OF THE FINDINGS: In 1979, Sillence et al. developed a classification of OI subtypes based on clinical features and disease severity: OI type I, mild, common, with blue sclera; OI type II, perinatal lethal form; OI type III, severe and progressively deforming, with normal sclera; and OI type IV, moderate severity with normal sclera. Approximately 90% of individuals with OI are heterozygous for mutations in the COL1A1 and COL1A2 genes, with dominant pattern of inheritance or sporadic mutations. After 2006, mutations were identified in the CRTAP, FKBP10, LEPRE1, PLOD2, PPIB, SERPINF1, SERPINH1, SP7, WNT1, BMP1, and TMEM38B genes, associated with recessive OI and mutation in the IFITM5 gene associated with dominant OI. Mutations in PLS3 were recently identified in families with osteoporosis and fractures, with X-linked inheritance pattern. In addition to the genetic complexity of the molecular basis of OI, extensive phenotypic variability resulting from individual loci has also been documented. CONCLUSIONS: Considering the discovery of new genes and limited genotype-phenotype correlation, the use of next-generation sequencing tools has become useful in molecular studies of OI cases. The recommendation of the Nosology Group of the International Society of Skeletal Dysplasias is to maintain the classification of Sillence as the prototypical form, universally accepted to classify the degree of severity in OI, while maintaining it free from direct molecular reference. .

OBJETIVO: Revisão da literatura sobre novos genes relacionados à osteogênese imperfeita (OI) e atualização da sua classificação. FONTE DOS DADOS : Revisão nas bases de dados do PUBMED e OMIM com seleção de referências relevantes. SÍNTESE DOS DADOS: Sillence et al., em 1979, desenvolveram uma classificação dos subtipos de OI baseada em características clínicas e gravidade da doença: OI tipo I, forma leve, comum, com escleras azuladas; OI tipo II, forma perinatal letal; OI tipo III, forma grave e progressivamente deformante com esclera normal; e OI tipo IV, forma de gravidade moderada com esclera normal. Cerca de 90% dos indivíduos com OI são heterozigotos para mutações em COL1A1 e COL1A2, com padrão de herança dominante ou esporádico. A partir de 2006 foram identificadas mutações nos genes CRTAP, FKBP10, LEPRE1, PLOD2, PPIB, SERPINF1, SERPINH1, SP7, WNT1, BMP1 e TMEM38B associadas à OI recessiva e mutação em IFITM5 associada à OI dominante. Mutações em PLS3 foram identificadas recentemente em famílias com osteoporose e fraturas, com padrão de herança ligado ao X. Além da complexidade genética das bases moleculares das OI, extensa variabilidade fenotípica resultante de loci individuais também tem sido documentada. CONCLUSÕES: Face à descoberta de novos genes e à correlação genótipo-fenótipo limitada, o uso de ferramentas de sequenciamento de nova geração torna-se útil no estudo molecular de casos de OI. A recomendação do Grupo de Nosologia da Sociedade Internacional de Displasias Esqueléticas é manter a classificação de Sillence como a forma prototípica e universalmente aceita para classificar o grau de gravidade na OI, e libertá-la de referência ...

Osteogénesis imperfecta: caso clínico / Osteogenesis imperfecta: report of a clinical case

Las displasias esqueléticas son un grupo de enfermedades de los huesos, de origen genético, tipo generalizado. Son enfermedades poco frecuentes. Se han descrito aproximadamente 350 tipos de displasias óseas diferentes. Dentro de éstas, se encuentra la osteogénesis imperfecta, en la que hay una alteración del colágeno tipo 1. Este colágeno se encuentra también en la conjuntiva, en los ligamentos y en los dientes; de allí que las manifestaciones pueden observarse también en áreas extraóseas. En el caso clínico, se describe la situación de una paciente pediátrica con diagnóstico de osteogéensis imperfecta tipo 1, la problemática de la enfermedad y las posibilidades de tratamiento odontológico.

Fanconi-Bickel syndrome versus osteogenesis imperfeeta: An Iranian case with a novel mutation in glucose transporter 2 gene, and review of literature.

Fanconi-Bickel syndrome is an extremely rare hereditary metabolic disease, characterized by hepatomegaly due to glycogen storage, refractory hypophosphatemic rickets, marked growth retardation and proximal renal tubular acidosis. Recurrent bone fractures are one of the hallmark findings. It is a single gene disorder; the responsible gene belongs to the facilitative glucose transporters 2 (GLUT2) family gene or (SLC2A2) mapped to the q26.1-26.3 locus on chromosome 3, and encodes the GLUT protein 2. This protein is expressed in pancreatic ί-cells, hepatocytes, renal tubules, and intestinal mucosa. Several mutations in the GLUT2 gene have been reported in different ethnicities. Herein we report an Iranian girl with a missed diagnosis of osteogenesis imperfecta. She was referred with the history of frequent fractures, and severe motor delay and was suspected to osteogenesis imperfecta. Following the case we detected refractory rickets instead of OI, sever growth failure, proximal renal tubulopathy and RTA, and enlarged kidneys, progressive hepatomegaly, and GSD on liver biopsy. Glucose and galactose tolerance tests confirmed abnormal carbohydrate metabolism. Molecular analysis on GLUT2 gene revealed a homozygous novel mutation in exon 5; it was 15 nucleotide deletion and 7 nucleotide insertion and caused a frame shift mutation, produced a premature truncated protein (P.A229QFsX19). This mutation has not been reported before in the relevant literature.

Implantes dentales en osteogénesis imperfecta. Niños con huesos de cristal: algo más que un caso clínico / Dental implants in osteogenesis imperfecta. Children with crystal bones: more than a clinical case

La osteogénesis imperfecta, también llamada enfermedad de los niños con huesos de cirstal, es una enfermedad genética. La misma se caracteriza porque los huesos se rompen tras un mínimo traumatismo e incluso sin causa. Su incidencia es alta. Puede no sercongénita. Se debe a la insuficiente y/o defectuosa formación del colágeno tipo I, que constituye el 85 a 90 por ciento del hueso. En tipos severos causa la muerte al nacer. Ha sido contraindicada la colocación de implantes. Este caso clínico de implantes fue exitoso en un Tipo moderado (IV) y se realizó a pedido del paciente, luego de explicársele la falta de antecedentesen la bibliografía y la contraindicación teórica.

Osteogénesis imperfecta: mosaicismo germinal o evidencia de heterogeneidad genética. Presentación de una familia y revisión bibliográfica / Osteogénesis imperfect: mosaicismo germinal or evidence of genetic heterogeneousness: presentation of a family and bibliographical review

La osteogénesis imperfecta clasifica entre las displasias óseas por alteraciones en la densidad y los defectos del modelaje óseo. El tipo I es la forma más frecuente de la enfermedad y se caracteriza por un patrón de herencia autosómico dominante. No es infrecuente que la enfermedad aparezca producto de una nueva mutación. También se ha demostrado que puede ser producida por mosaicismos germinales. Este trabajo documenta, por primera vez en Cuba, el caso de una familia con 3 individuos de diferente sexo afectados por osteogénesis imperfecta de tipo I mientras ninguno de los progenitores lo está. Se discute la posibilidad etiológica de un mosaicismo germinal y se valora asimismo la posibilidad de un patrón de herencia distinto del dominante, lo cual aportaría nueva evidencia de heterogeneidad genética.

Osteogenesis imperfecta is one of the bone dysplasias caused by altered density and bone model defects. Type I is the most common form of disease and is characterized by an autosomal dominant inheritance pattern. Sometimes, this disease occurs as a result of a new mutation. It has been also demonstrated that it can be caused by germ mosaicisms. This paper documented for the first time in Cuba the case of a family with three (3) individuals of both sexes affected by type-1 osteogenesis imperfecta but their parents were not. The etiological possibilities of germ mosaicism and the possibilities of an inheritance pattern different from the dominant one were discussed, which would give new genetic heterogeneity evidence.

Tratamiento de osteogénesis imperfecta con bisfosfonatos / Treatment of osteogenesis imperfecta with bisphosphonates

El tratamiento con bisfosfonatos (BP), ha mejorado la calidad de vida de los pacientes con osteogénesis imperfecta (OI). Los efectos benéficos son el alivio del dolor, la reducción de la incidencia de fracturas, la mejor movilidad corporal y la recuperación en las formas vertebrales. El tratamiento es más efectivo durante el período de crecimiento. Se presenta una actualización del tema. De la lectura de los anales se destacan los siguientes interrogantes: ¿Por cuánto tiempo deberá instituirse el tratamiento? ¿Es la vía oral tan efectiva como la endovenosa? ¿Cuál es la mejor dosis? ¿Cuándo suspender el tratamiento? ¿Se conservará la integridad del tejido óseo después de un tratamiento prolongado? ¿Qué fenómenos ocurren en el tejido óseo después de la interrupción de la terapia?.

Treatment with bisphosphonates (BP) improves the quality of life of patients with osteogenesis imperfecta (OI). Beneficial effects are the relief of bone pain, a reduction of fracture incidence, improvement of corporal mobility and recovery of normal vertebral form. Treatment is less effective after completion of growth is here. An update of the literature is here presented. A number of important unsolved questions have been pointed out: for how long should treatment be instituted? Is the oral route as effective as the intravenous one? Which is the best dose? When treatment should be stopped? How well preserved is the longterm integrity of the bones? Which are the phenomena occurring in bone tissue after interruption of therapy?.

Osteogénesis imperfecta: caso clínico y actualización / Osteogenesis imperfecta clinical and case updates

Se presenta un caso de osteogénesis imperfecta, atendido en el Hospital Arco Iris, en un niño de 8 años de edad que presenta severas deformaciones en ambos miembros pélvicos, con antecedentes de fracturas múltiples desde su infancia, varias por traumas de baja energia, no habiendo alcanzado nunca la bipedestación ni la marcha. Se hace interesante por la poca frecuencia de la presentación de esta enfermedad y por la severidad de las deformidades en miembros pélvicos. La conducta quirúrgica fue realizada según protocolo y técnica de Sofield Millar en ambos segmentos de los miembros pélvicos, obteniendo resultados muy alentadores, e indiscutiblemente se trata de un caso que requirió de experiencia y habilidad en su manejo, con el afán de integrar a este paciente a una vida lo más cercana a la normalidad, lo cual se logra luego de la rehabilitación, hasta conseguir la marcha con ayuda de dos muletas. Se aprovecha la presentación del caso para realizar una revisión de la literatura actualizada en cuanto al diagnóstico y tratamiento médico y quirúrgico de Osteogénesis imperfecta, así como la nueva clasificación en 7 tipos, 3 más que los originales de Sillence.

A case of Osteogenesis Imperfecta, treated in the Hospital ArcoIris, in an 8 year-old male child with severe deformations in bothlower extremities, and several fractures caused by traumas oflow energy since childhood. The boy never reached the standingposition or walking ability. The case is interesting due to the lowfrequency of this disease and the severity of the deformities in thelower extremities. The surgical procedure was made according tothe technical protocol of Sofield Millar in both segments of the lowerextremities, obtaining very encouraging results. Unquestionably, thiswas a case that required much experience and ability in its handling,with the wish to integrate this patient to a life as normal as possible,which was obtained after rehabilitation, until reaching walking abilitywith the help of two crutches. This report takes advantage of thecase to make a review of the updated literature as far as diagnosisand treatment, medical and surgical procedure of OsteogenesisImperfecta are concerned, as well as on the new classification in 7types, 3 more than the original ones of Sillence.

Clinical and Radiological Manifestations of Osteogenesis Imperfecta Type V

We reviewed clinical manifestation of 12 patients from three Korean families. They showed mild to moderate bone fragility, and suggested an autosomal dominant inheritance pattern. Significant intrafamilial phenotype variability was obvious. Clinical, radiological, and histopathologic characteristics that distinguished this subtype from others include ossification of interosseous membrane of the forearm with radial head dislocation, hyperplastic callus formation, no evidence of type I collagenopathy and an abnormal histopathologic pattern. Severity of the interosseous membrane ossification was correlated with increasing age (p<0.01) and the radial head dislocation was thought to be a developmental problem rather than a congenital problem. Four children who had bisphosphonate treatment showed improved bone mineral density, radiological changes, and biochemical responses. Osteogenesis imperfecta type V was a distinctive subtype of osteogenesis imperfecta, which caused mild to moderate disability clinically.

Terapia génica y sus perspectivas clínicas en ortopedia / Gene therapy and its clinical perspectives in orthopaedics

La terapia génica se refiere a la transferencia de genes a individuos con fines terapéuticos. Esta técnica se ha desarrollado durante los últimos 10 años y tiene aplicaciones en todas las áreas de la medicina. Originalmente dirigida al tratamiento de padecimientos congénitos, actualmente también se estudian sus posibles aplicaciones en el tratamiento de padecimientos adquiridos. Presentamos los conceptos generales de la terapia génica y sus posibles aplicaciones en ortopedia como futuras opciones terapéuticas

Osteogênese imperfeita-forma letal: estudo genético clínico, radiológico e anatomopatológico de três casos / Imperfecta osteogenesis - lethal form: Clinical genetic, radiologic estudy

Apresentamos três casos de Osteogênese imperfeita tipo II (forma letal). A investigaçäo foi realizada pela descriçäo fenotípica, antropometria, estudo radiológico e necropsia. Foram selecionados de uma amostra de casos de osteocondrodisplasias letais. Dois dos casos apresentavam a forma IIA da osteogênese Imperfeita enquanto que o último caso, IIB. A sistematizaçäo diagnóstico é fundamental pois trata-se de patologia heterogênea do ponto de vista genético. Assim, o diagnóstico preciso dos subtipos é fundamental para o aconselhamento genético

new concept in diagnosis of osteogenesis imperfecta

Eighteen patients with osteogenesis imperfecta were studied from July 1985 to July 1991. 83.33% of them had HLA-B 35. It is regarded as a helpful method in confirming the diagnosis in patients with mild signs of the disease

Ostegénesis imperfecta tipo II en un recién nacido: importancia de su reconocimiento para un asesoramiento genético a los padres / Type II osteogenesis imperfect in newborn : the importance of diagnosis for genetical counseling of the parents

Reportamos el caso de un natimuerto de 36 semanas de edad gestacional nacido en el hospital Nuestra Sra. de la Altagracia de Higuey, el cual presentó Osteogenesis Imperfecta tipo-II. Se señala la importancia de definir el tipo de Osteogénesis, pues los riesgos de recurrencia varian segun la etiologia. La fotografia tomada a este paciente permitio hacer el diagnostico y dar asesoria genetica a sus padres