Displasia frontometafisaria 2 asociada con deformidad torácica e hipertensión arterial pulmonar: a propósito de un caso y revisión bibliográfica / Frontometaphyseal dysplasia 2 associated with thoracic deformity, and pulmonary arterial hypertension: a case report and review of literature

La displasia frontometafisaria 2 (DFM2) es una enfermedad rara causada por una mutación en el gen MAP3K7. En este artículo, se informa sobre un paciente de 7 años con DFM2 causada por una variante nueva de corte y empalme en MAP3K7. El paciente presenta las características frecuentes de la DFM2, pero algunas nunca antes informadas. No se dispone de una descripción sistemática de las características de las imágenes tomográficas de la DFM2. Describimos ciertas diferencias en las características de la DFM2, la bibliografía publicada y las manifestaciones imagenológicas generales de la DFM2. Este caso resalta la importancia del valor clínico de la tomografía computada (TC) y la renderización de volúmenes (VR) en el diagnóstico de la DFM2. Las características de la DFM2 pueden observarse claramente en los estudios tomográficos, lo que señala la gran importancia de la TC para el diagnóstico y el tratamiento precoces de los pacientes con DFM2.

Frontometaphyseal dysplasia 2 (FMD2) is a rare disease caused by MAP3K7 gene mutation. We report a 7-year-old sporadic patient with FMD2 due to a de novo splicing variant in MAP3K7. He has the common characteristics of FMD2 but also has some characteristics that have never been reported, which increases the clinical phenotype of FMD2. Moreover, no systematic description of the imaging characteristics of FMD2 in computed tomography (CT) is available. In the present work, we found some different features of FMD2, reviewed previous literature, and summarized the general imaging manifestations of FMD2. This case emphasizes the important clinical value of CT and VR in the diagnosis of FMD2. We can clearly find the characteristics of FMD2 by CT examination, indicating its great significance for the prompt diagnosis and treatment of FMD2 patients.

Clinical features and FGFR3 mutations of children with achondroplasia / 中国当代儿科杂志

OBJECTIVES@#To study the clinical features and fibroblast growth factor receptor 3 (FGFR3) gene mutations of children with achondroplasia (ACH) through an analysis of 17 cases.@*METHODS@#A retrospective analysis was performed on the clinical data and FGFR3 gene detection results of 17 children with ACH who were diagnosed from January 2009 to October 2021.@*RESULTS@#Of the 17 children with ACH, common clinical manifestations included disproportionate short stature (100%, 17/17), macrocephaly (100%, 17/17), trident hand (82%, 14/17), and genu varum (88%, 15/17). The common imaging findings were rhizomelic shortening of the long bones (100%, 17/17) and narrowing of the lumbar intervertebral space (88%, 15/17). Major complications included skeletal dysplasia (100%, 17/17), middle ear dysfunction (82%, 14/17), motor/language developmental delay (88%, 15/17), chronic pain (59%, 10/17), sleep apnea (53%, 9/17), obesity (41%, 7/17), foramen magnum stenosis (35%, 6/17), and hydrocephalus (24%, 4/17). All 17 children (100%) had FGFR3 mutations, among whom 13 had c.1138G>A hotspot mutations of the FGFR3 gene, 2 had c.1138G>C mutations of the FGFR3 gene, and 2 had unreported mutations, with c.1252C>T mutations of the FGFR3 gene in one child and c.445+2_445+5delTAGG mutations of the FGFR3 gene in the other child.@*CONCLUSIONS@#This study identifies the unreported mutation sites of the FGFR3 gene, which extends the gene mutation spectrum of ACH. ACH is a progressive disease requiring lifelong management through multidisciplinary collaboration.

Clinical and genetic analysis of a Chinese pedigree affected with Dyggve-Melchior-Clausen syndrome due to a novel frameshift variant of DYM gene / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis of a Chinese pedigree affected with Dyggve-Melchior-Clausen syndrome.@*METHODS@#Whole exome sequencing and Sanger sequencing were carried out to detect potential pathogenic variants associated with the syndrome. The function of candidate variant was verified by Western blotting.@*RESULTS@#A novel homozygous variant, c.1222delG of the DYM gene was detected in the two affected siblings, for which both parents were heterozygous carriers. The variant has caused replacement of Asp by Met at amino acid 408 and generate a premature stop codon p.Asp408Metfs*10. Western blotting confirmed that the variant can result in degradation of the mutant DYM protein, suggesting that it is a loss of function variant.@*CONCLUSION@#The homozygous c.1222delG frameshift variant of the DYM probably underlay the Dyggve-Melchior-Clausen syndrome in the two affected siblings. Above findings has enabled clinical diagnosis and genetic counseling for the family.

Afectación respiratoria en paciente con acrodisostosis: una asociación infrecuente de una enfermedad rara / Respiratory impairment in a patient with acrodysostosis: A rare association of an uncommon pathology

La acrodisostosis es una displasia esquelética rara, de herencia autosómica dominante, que se caracteriza por la presencia de disostosis facial y periférica, talla baja y diferentes grados de obesidad. La acrodisostosis de tipo 1, secundaria a la mutación heterocigota en el gen PRKAR1A (17q24.2), se caracteriza por la asociación de resistencia hormonal múltiple con anomalías esqueléticas. Su incidencia está infradiagnosticada debido a que comparte rasgos clínicos y de laboratorio con otras entidades como el seudohipoparatiroidismo. Presentamos el caso de una niña de 8 años, con acrodisostosis tipo 1, confirmada mediante estudio genético. Además del fenotipo característico descrito, la talla baja y la resistencia hormonal, la paciente presentó una afectación progresiva de la función pulmonar: un patrón pulmonar obstructivo no reversible. En la literatura revisada, no se han encontrado otros casos que describan esta asociación entre acrodisostosis y afectación respiratoria.

Acrodysostosis is a rare skeletal displasia, of autosomal dominant inheritance, characterized by the presence of facial and peripheral dysostosis, short stature and obesity. Type 1 acrodysostosis is secondary to a mutation in the PRKAR1A (17q24.2) gene, which results in multi hormonal resistance and skeletal anomalities. This syndrome is under-diagnosed as it shares analytical and clinical characteristics with other entities, such as pseudohypoparathyroidism. We report the case of an eight-year-old girl with genetically confirmed type 1 acrodysostosis. In addition to the characteristic phenotype described, the short stature and the hormonal resistance, the patient suffered a progressive lung function deterioration: an irreversible pulmonary obstructive pattern. We have not found in previous literature cases reporting an association between acrodysostosis and lung function impairement.

Frontometaphyseal dysplasia 1 caused by variant of FLNA gene in a case / 中华医学遗传学杂志

OBJECTIVE@#To explore the clinical and genetic characteristics of a child with frontometaphyseal dysplasia 1 (FMD1) due to variant of FLNA gene.@*METHODS@#Clinical phenotype of the patient was analyzed. Whole exome sequencing (WES) was carried out to detect pathogenic genetic variants. Sanger sequencing was used to verify the result in his parents.@*RESULTS@#The 2-year-and-9-month-old boy presented with facial dysmorphism (supraorbital hyperostosis, down-slanting palpebral fissure and ocular hypertelorism), skeletal deformities (bowed lower limbs, right genu valgum, left genu varus, slight deformity of index and middle fingers, and flexion contracture of little fingers). He also had limited left elbow movement. High-throughput sequencing revealed that he has carried a de novo heterogeneous c.3527G>A (p.Gly1176Glu) missense variant of the FLNA gene. The same variant was found in neither parent.@*CONCLUSION@#The clinical manifestations of FMD1 such as joint contracture and bone dysplasia can occur in infancy and deteriorate with age, and require long-term follow-up and treatment. Above finding has expanded the spectrum of FLNA gene variants.

Diagnosis of atelosteogenesis type I suggested by fetal ultrasonography and atypical paternal phenotype with mosaicism / Diagnóstico de atelosteogênese tipo I sugerido por ultrassonografia fetal e fenótipo paterno atípico com mosaicismo

Abstract Atelosteogenesis type I (AOI) is an autosomal dominant skeletal dysplasia caused by mutations in the filamin B (FLNB) gene with classic and well-recognizable clinical findings. However, parents affected with a mild phenotype, probably with somatic mosaicism, can generate offspring with a much more severe phenotype of AOI. In the present report, we describe a female newborn with classic AOI leading to early neonatal death, whose diagnostic was based on prenatal radiological findings and on the physical examination of the father. Since her father had limb deformities and corporal asymmetry, suggesting somatic mosaicism, his biological samples were analyzed through a gene panel for skeletal dysplasias. A missense mutation not previously described in the literature was detected in the FLNB gene, affecting ~ 20% of the evaluated cells and, therefore, confirming the diagnosis ofmosaic AOI in the father. The molecular analysis of the father was crucial to suggest the diagnosis of AOI in the newborn, since she died early and there were no biological samples available.

Resumo A atelosteogênese tipo I (AOI) é uma displasia esquelética autossômica dominante causada por mutações no gene filamina B (FLNB) comachados clínicos clássicos e bem reconhecíveis. No entanto, pais afetados com um fenótipo mais leve, provavelmente commosaicismo somático, podem gerar uma prole comumfenótipomuito mais grave de AOI. No presente relato, descrevemos um recém-nascido do sexo feminino comAOI clássica, que levou à morte neonatal precoce, e cujo diagnóstico foi baseado em achados radiológicos pré-natais e no exame físico de seu genitor. Como o genitor apresentava deformidades em membros e assimetria corporal, que sugeriam mosaicismo somático, suas amostras biológicas foram analisadas por meio de um painel de genes para displasias esqueléticas. Umamutação missense, não descrita anteriormente na literatura, foi detectada no gene FLNB, afetando ~ 20% das células avaliadas, e, portanto, confirmando o diagnóstico de AOI em mosaico no genitor. A análise molecular realizada no genitor foi fundamental para sugerir o diagnóstico de AOI na recém-nascida, uma vez que esta morreu precocemente, e não havia amostras biológicas disponíveis.

Identification of a De Novo Heterozygous Missense FLNB Mutation in Lethal Atelosteogenesis Type I by Exome Sequencing

BACKGROUND: Atelosteogenesis type I (AO-I) is a rare lethal skeletal dysplastic disorder characterized by severe short-limbed dwarfism and dislocated hips, knees, and elbows. AO-I is caused by mutations in the filamin B (FLNB) gene; however, several other genes can cause AO-like lethal skeletal dysplasias. METHODS: In order to screen all possible genes associated with AO-like lethal skeletal dysplasias simultaneously, we performed whole-exome sequencing in a female newborn having clinical features of AO-I. RESULTS: Exome sequencing identified a novel missense variant (c.517G>A; p.Ala173Thr) in exon 2 of the FLNB gene in the patient. Sanger sequencing validated this variant, and genetic analysis of the patient's parents suggested a de novo occurrence of the variant. CONCLUSIONS: This study shows that exome sequencing can be a useful tool for the identification of causative mutations in lethal skeletal dysplasia patients.

Hypoparathyroidism-retardation-dysmorphism syndrome.

Congenital hypoparathyroidism, growth retardation and facial dysmorphism is a rare autosomal recessive disorder seen among children born to consanguineous couple of Arab ethnicity. This syndrome is commonly known as Sanjad- Sakati or hypoparathyroidism‑retardation‑dysmorphism syndrome (HRD). We report 13‑year‑old Hindu boy with hypoparathyroidism, tetany, facial dysmorphism and developmental delay, compatible with HRD syndrome.

Síndrome otopalatodigital tipo II, aproximación prenatal y diagnóstico clínico de un caso complejo de displasia ósea / Prenatal diagnosis of otopalatodigital syndrome type 2

El síndrome otopalatodigital tipo 2 (OPD2), es una rara entidad con herencia recesiva ligada al cromosoma X, letal, caracterizada por facies anormales con hipoplasia centrofacial, hipertelorismo ocular, paladar hendido, talla baja, huesos largos curvos, sindactilia en pies y manos y anomalías óseas. Usualmente originadas en mutaciones en el gen de la filamina A (FLNA). Se reporta un caso, con diagnóstico prenatal de osteocondrodisplasia que posteriormente por hallazgos al examen físico y radiológicos del recién nacido se clasifico como síndrome otopalatodigital tipo 2.

Otopalatodigital syndrome, type 2 (OPD2), is a rare entity with recessive heredity linked to the X chromosome, lethal, characterized by abnormal facies, with centro-facial hypoplasia, ocular hypertelorism, cleft palate, low height, curved long bones, syndactyly, and osseous anomalies on feet and hands. It has been recently shown that patients with OPD2 with mutations in the filamin A gene (FLNA), which is also found altered in allelic entities like the OPD1 syndrome, the Melnik-Needles syndrome and frontometaphyseal dysplasia. Herein, we report a case with prenatal osteochondrodysplasia diagnosis that after physical and radiological exam of the newborn was classified as otopalatodigital syndrome type 2.

Human skeletal dysplasia caused by a constitutive activated transient receptor potential vanilloid 4 (TRPV4) cation channel mutation

The transient receptor potential vanilloid 4 (TRPV4) cation channel, a member of the TRP vanilloid subfamily, is expressed in a broad range of tissues where it participates in the generation of Ca2+ signals and/or depolarization of the membrane potential. Regulation of TRPV4 abundance at the cell surface is critical for osmo- and mechanotransduction. Defects in TRPV4 are the cause of several human diseases, including brachyolmia type 3 (MIM:113500) (also known as brachyrachia or spondylometaphyseal dysplasia Kozlowski type [MIM:118452]), and metatropic dysplasia (MIM:156530) (also called metatropic dwarfism or parastremmatic dwarfism [MIM:168400]). These bone dysplasia mutants are characterized by severe dwarfism, kyphoscoliosis, distortion and bowing of the extremities, and contractures of the large joints. These diseases are characterized by a combination of decreased bone density, bowing of the long bones, platyspondyly, and striking irregularities of endochondral ossification with areas of calcific stippling and streaking in radiolucent epiphyses, metaphyses, and apophyses. In this review, we discuss the potential effect of the mutation on the regulation of TRPV4 functions, which are related to human diseases through deviated function. In particular, we emphasize how the constitutive active TRPV4 mutant affects endochondral ossification with a reduced number of hypertrophic chondrocytes and the presence of cartilage islands within the zone of primary mineralization. In addition, we summarize current knowledge about the role of TRPV4 in the pathogenesis of several diseases.

X-Linked Spondyloepiphyseal Dysplasia Tarda: Identification of a TRAPPC2 Mutation in a Korean Pedigree

Spondyloepiphyseal dysplasia (SED) comprises a heterogeneous group of skeletal dysplasias that primarily affect the epiphyses and vertebral bodies. Patients affected by SED usually exhibit short stature and experience early development of degenerative osteoarthritis. SED is subdivided into congenita and tarda forms according to the age at onset and clinical severity, and further subdivided into genetically different forms according to the mode of inheritance and the gene involved. We report a 14-yr-old Korean male who presented with a disproportionately short stature and a short trunk. A pedigree analysis of 3 generations with 6 affected persons revealed an X-linked recessive mode of inheritance. Mutation analysis of the TRAPPC2 (previously called SEDL) gene, the only gene associated with X-linked spondyloepiphyseal dysplasia tarda (X-linked SEDT; MIM 313400), was performed, and a splice-donor site mutation in intron 3 of the TRAPPC2 gene (c.93+5G>A) was identified in the proband and in his unaffected mother (a heterozygote). This mutation is one of the 2 most frequent mutations reported in the medical literature, and is known to result in exon 3 skipping. This is the first report of a genetically confirmed X-linked SEDT case in Korea and highlights the importance of recognizing the mode of inheritance in the diagnosis of X-linked SEDT.

A recurrent mutation in Moroccan patients with Dyggve-Melchior-Clausen syndrome: Report of a new case and review.

Dyggve-Melchior-Clausen (DMC) syndrome is a rare autosomal recessive disorder. It is a spondyloepimetaphyseal dysplasia associated with mental retardation. Clinical manifestations include coarse facies, microcephaly, short trunk dwarfism, and mental retardation. Mutations in Dymeclin gene (DYM), mapped to chromosome 18q21.1, is responsible for DMC. We report here the observation of a consanguineous Moroccan patient having DMC syndrome. The molecular studies showed a previously reported homozygous mutation at c.1878delA of DYM gene. We discuss this recurrent mutation in Moroccan patients with DMC syndrome with a review.

Displasia espóndilo-epifisiaria asociada a cráneo-sinostosis, cataratas, paladar hendido y retardo mental: Reporte de un caso / Spondylo-epiphyseal dysplasia associated with craniosynostosis, cleft palate and mental retardation: A case report

Las displasias esqueléticas son un grupo muy heterogéneo de trastornos que se caracterizan por una alteración en la organización del tejido óseo, lo que causa una distorsión en su patrón de crecimiento y desarrollo. En 1998, se descibió el caso de cuatro hermanos japoneses, tres varones y una hembra que presentaban una displasia espóndilo-epifisiaria, no descrita anteriormente, asociada con cráneo-sinostosis, cataratas, paladar hendido y retardo mental de diferente grado. Se planteó una probable herencia autosómica recesiva, debido a que las alteraciones afectaban a ambos sexos y los padres eran fenotípicamente sanos, aunque con discreto retardo mental; sin embargo, no fue posible descartar un mosaicismo germinal. El caso que se presenta, trata de un paciente con signos clínicos y radiológicos que coinciden con los previamente descritos. Es producto de padres consanguíneos en la segunda generación, lo cual se sumaría a la presunción ya postulada, de una probable mutación de herencia autosómica recesiva. La presente comunicación, representa el segundo reporte en la literatura, del quinto caso descrito y el segundo grupo familiar con la afección mencionada.

Skeletal dysplasias are a heterogeneous group of disorders characterized by an alteration of the organization of osseous tissue causing a distortion on the growth and development pattern of bones. In 1998, four Japanese sibs were described by the first time, three males and one female who presented a previously undescribed spondylo-epiphyseal dysplasia associated with craniosynostosis, cataracts, cleft palate and different grades of mental retardation. A probable autosomic recessive inheritance was suggested, but a germinal mosaicism could not be discarded. This is a case report of a patient with clinical and radiological findings similar to the ones previously described, born to second degree consanguineous parents. This supports the postulated presumption of a mutation with an autosomic recesive inheritance. The present comunication represents the fifth case reported in the literature and the second familiar group affected.

Autosomal Recessive Multiple Epiphyseal Dysplasia in a Korean Girl Caused by Novel Compound Heterozygous Mutations in the DTDST (SLC26A2) Gene

Multiple epiphyseal dysplasia is caused by heterogenous genotypes involving more than six genes. Recessive mutations in the DTDST gene cause a phenotype of recessive multiple epiphyseal dysplasia (rMED). The authors report a 9-yr old Korean girl with the rMED phenotype having novel compound heterozygous mutations in the DTDST gene, which were inherited from both parents. This is the first Korean rMED case attributed to DTDST mutations, and expands the spectrum of diseases caused by DTDST mutations.

An illustrative case of Léri-Weill dyschondrosteosis

We report on a girl presenting Léri-Weill dyschondrosteosis (LWD) due to deletion of the SHOX gene. Her family included individuals with short stature alone or with both short stature and mesomelia or Madelung's deformity. The deletion was demonstrated through detection of hemizygosity for microsatellite markers SHOX-CA repeat, DXYS10092, DXYS10093 and DXYS10091 localized around the SHOX gene, with retention of paternal alleles in the proband and three of her sisters who had short stature as the only clinical feature. Hemizygosity for these loci was also observed in their mother, who had short stature too. The deletion in the proband was however larger, including locus DXY10083. The proband's only sister with normal height did not carry the deletion. Family history suggests transmission of the deletion from the proband's maternal great-grandfather to her grandfather via the Y chromosome, and from the grandfather to the proband's mother via the X chromosome after crossing-over in the pseudoautosomal region proximal to the SHOX gene.

Cryptic intragenic deletion of the SHOX gene in a family with Léri-Weill dyschondrosteosis detected by Multiplex Ligation-Dependent Probe Amplification (MLPA) / Deleção críptica intragênica do gene SHOX em uma família com discondrosteose de Léri-Weill detectada por Multiplex Ligation-Dependent Probe Amplification (MLPA)

LWD is associated to SHOX haploinsufficiency, in most cases, due to gene deletion. Generally FISH and microsatellite analysis are used to identify SHOX deletion. MLPA is a new method of detecting gene copy variation, allowing simultaneous analysis of several regions. Here we describe the presence of a SHOX intragenic deletion in a family with LWD, analyzed through different methodologies. Genomic DNA of 11 subjects from one family were studied by microsatellite analysis, direct sequencing and MLPA. FISH was performed in two affected individuals. Microsatellite analysis showed that all affected members shared the same haplotype suggesting the involvement of SHOX. MLPA detected an intragenic deletion involving exons IV-VIa, which was not detected by FISH and microsatellite analysis. In conclusion, the MLPA technique was proved to be the best solution on detecting this small deletion, it has the advantage of being less laborious also allowing the analysis of several regions simultaneously.

Discondrosteose de Léri-Weill (DLW) está associada à haploinsuficiência do gene SHOX resultante, principalmente, de deleções. Geralmente, o FISH e a análise de microssatélites são os métodos utilizados para a identificação destas deleções. MLPA é um novo método para detectar variações do número de cópias gênicas, permitindo uma análise simultânea de várias regiões. Aqui, descrevemos uma pequena deleção intragênica no SHOX em uma família com DLW analisada por diferentes metodologias. DNA genômico de 11 membros de uma família foram estudados por microssatélites, seqüenciamento direto e MLPA. FISH foi realizado em dois indivíduos afetados. Os microssatélites demonstraram que todos os membros afetados apresentavam o mesmo haplotipo, sugerindo o envolvimento do SHOX. MLPA identificou uma deleção intragênica envolvendo os éxons IV-VIa, que não foi detectada pelo FISH e pelos microssatélites. Conclui-se que o MLPA demonstrou melhor resolução para detectar esta pequena deleção, com a vantagem de ser menos trabalhoso e permitir a análise de várias regiões simultaneamente.

Schwartz-Jampel syndrome: a case report

Schwartz-Jampel syndrome is a rare autosomal recessive disorder in which the patient had short stature, myotonia with paucity of facial expression, blepharophimosis, pectus carinatum, and contractures. It is a muscle-joint anomaly with prominent facial characteristics and ocular defects. There is a typical facial appearance due to myotonia of the muscles of expression; the skin appears to be pursed and stretched tightly over the face and mouth. Joint limitations are part of the syndrome. The face appears somewhat expressionless, and the few patients who have been identified to have a remarkably consistent appearance. Blepharophimosis is a consistent feature. We report the occurrence of the classic Schwartz-Jampel syndrome in two boys of two consanguineous families in Jordan with bilateral congenital nasolacrimal duct obstruction in one of them. Their main facial manifestations are highlighted