Usefulness of the MS-MLPA technique in the diagnosis of Beckwith-Wiedemann syndrome and Silver-Russell syndrome.

INTRODUCTION: Epigenetic and genomic imprinting alterations of the 11p15.5 region cause excessive or deficient growth, which result in Beckwith-Wiedemann syndrome (BWS) or Silver-Russell syndrome (SRS), respectively. OBJECTIVE: To evaluate the methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA) methylation analysis technique in the diagnosis of BWS and SRS. METHODS: 11p15.5 methylation and variants were evaluated in patients with clinical diagnosis of BWS and SRS using the MS-MLPA technique in peripheral blood DNA. RESULTS: Paternal uniparental disomy and loss of maternal IC2 methylation were identified in two patients with BWS who had omphalocele and macroglossia, respectively. Paternal IC1hypomethylation was recorded in two patients with SRS of classic phenotype. CONCLUSIONS: Adequate genotype-phenotype correlation was observed with the methylation defects that were identified, which confirms the usefulness of MLPA as a first-line study in patients diagnosed with BWS and SRS.

INTRODUCCIÓN: Las alteraciones epigenéticas y genómicas de la región improntada 11p15.5 producen crecimiento excesivo o deficiente, que se manifiesta como síndrome de Beckwith-Wiedemann o síndrome de Silver-Russell, respectivamente. OBJETIVO: Evaluar la técnica de análisis de metilación MLPA (MS-MLPA, methylation-specific multiplex ligation-dependent probe amplification) en el diagnóstico de los síndromes de Beckwith-Wiedemann y de Silver-Russell. MÉTODOS: Se evaluó la metilación y las variantes de 11p15.5 en pacientes con diagnóstico clínico de síndrome de Beckwith-Wiedemann y síndrome de Silver-Russell mediante la técnica MS-MLPA en ADN de sangre periférica. RESULTADOS: Se identificó disomía uniparental paterna y pérdida de metilación del IC2 materno en dos pacientes con síndrome de Beckwith-Wiedemann, quienes presentaron onfalocele y macroglosia, respectivamente. Se registró hipometilación paterna del IC1 en dos pacientes con síndrome de Silver-Russell de fenotipo clásico. CONCLUSIONES: Se observó adecuada correlación genotipo-fenotipo con los defectos de metilación encontrados, lo que confirma la utilidad del MLPA como estudio de primera línea en pacientes con diagnóstico de síndrome de Beckwith-Wiedemann y síndrome de Silver-Russell.

Extracranial midline defects in a patient with craniofrontonasal syndrome with a novel EFNB1 mutation.

We report a female patient with craniofrontonasal syndrome (CFNS) who in addition showed other cranial and extracranial midline defects including partial corpus callosum agenesis, ocular melanocytosis, pigmentary glaucoma, duplex collecting system, uterus didelphys, and septate vagina. She was found to have a novel pathogenic variant in exon 5 of EFNB1, c.646G>T (p.Glu216*) predicted to cause premature protein truncation. From our review, we found at least 39 published CFNS patients with extracranial midline defects, comprising congenital diaphragmatic hernia, congenital heart defects, umbilical hernia, hypospadias, and less frequently, sacrococcygeal teratomas, and internal genital anomalies in females. These findings support that the EFNB1 mutations have systemic consequences disrupting morphogenetic events at the extracranial midline. Though these are not rigorously included as midline defects, we found at least 10 CFNS patients with congenital anomalies of the kidney and urinary tract, all females. Additionally, uterus didelphys and ocular melanocytosis observed in our patient are proposed also as a previously unreported EFNB1-related midline defects. In addition, this case may be useful for considering the intentional search for genitourinary anomalies in future patients with CFNS, which will be helpful to define their frequency in this entity.

A Family with EEC Syndrome in the Son and ADULT Syndrome in His Father Caused by the c.797G>A (p.Arg266Gln) Pathogenic Variant in the TP63 Gene.

Introduction: To our knowledge, there are few examples of intrafamilial variability involving two different TP63-linked morphopathies within a same family. Here, we describe a Mexican family in which the son had ectrodactyly, ectodermal dysplasia, and cleft lip/palate syndrome 3 (EEC3), and his father acro-dermato-ungual-lacrimal-tooth (ADULT) syndrome, both heterozygous for the p.Arg266Gln pathogenic variant in TP63. Additionally, we reviewed the clinical information reported for this TP63 genotype. Case Presentation: The son of this family presented ectodermal defects (thin and sparse hair, mild nail dysplasia), tetramelic ectrodactyly, syndactyly, and nasolacrimal duct obstruction (NLDO), indicative of an EEC3 diagnosis. His father, however, exhibited severe NLDO, facial freckling, dental abnormalities, mild nail dysplasia, and a history of micturition problems, compatible with ADULT syndrome. Both were heterozygous for the NM_003722.5(TP63):c.797G>A (p.Arg266Gln) pathogenic variant in TP63. Discussion: This report expands the spectrum of intrafamilial variability confirming that this can include the expression of distinct types of TP63-related disorders among different members of the same family, whose implications should be also considered in genetic counseling. From our review, we observed that p.Arg266Gln variant seems to correlate particularly with the presence of NLDO, sparse hair/eyebrows, ridged/dystrophic nails, anodontia/hypodontia, and micturition difficulties, as well as for a minor frequency of cleft lip/cleft palate.

[Prader-Willi and Angelman syndromes: case series diagnosed by MS-MLPA assay]. / Síndromes Prader-Willi y Angelman: serie de casos diagnosticados mediante la técnica de MS-MLPA.

BACKGROUND: Prader Willi syndrome (PWS) and Angelman syndrome (AS) are neurodevelopmental disorders caused by deletions or methylation defects, making a loss of expression of imprinted genes located in the 15q11-q13 region, and these can be assessed by different cytogenomic and molecular techniques. We report a case series of patients with PWS and AS evaluated through the MS-MLPA assay. CLINICAL CASES: We studied four patients with a clinical diagnosis of PWS and another with AS, evaluated as far as possible with karyotype and FISH, and with MS-MLPA assay for the 15q11-q13 region in all cases. In patients with PWS, neonatal hypotonia was the main reason for consultation and in three of them we identified a deletion of 15q11-q13 by MS-MLPA, also confirmed by FISH; and in the other one, an abnormal methylation pattern consistent with a maternal uniparental disomy. The patient with AS presented with a typical picture which led to the identification of a deletion in 15q11-q13 by MS-MLPA, also confirmed by FISH. CONCLUSIONS: The use of the MS-MLPA assay for the 15q11-q13 region was very useful for the diagnosis and identification of the genomic and epigenetic defects involved in either PWS and AS.

INTRODUCCIÓN: el síndrome Prader-Willi (SPW) y el síndrome de Angelman (SA) son trastornos del neurodesarrollo producidos por deleciones o defectos de metilación que producen pérdida de expresión en los genes improntados de la región 15q11 q13, mismos que pueden ser evaluados por diferentes técnicas citogenómicas y moleculares. Presentamos una serie de pacientes con SPW y SA en los que se identificó el tipo de defecto de la región 15q11-q13 mediante la técnica de MS-MLPA. CASOS CLÍNICOS: estudiamos cuatro pacientes con diagnóstico clínico de SPW y uno con SA, evaluados en lo posible con cariotipo, FISH y todos con ensayo MS-MLPA para la región 15q11-q13. En los pacientes con SPW, la hipotonía neonatal fue el motivo principal de consulta. En tres de ellos se identificó deleción de 15q11-q13 por MS-MLPA, confirmada por FISH, y en uno el patrón de metilación anormal fue compatible con una disomía uniparental materna. El paciente con SA presentó un cuadró típico y también se identificó una deleción en 15q11-q13 por MS-MLPA, confirmada por FISH. CONCLUSIONES: confirmamos que el uso de la técnica de MS-MLPA para la región 15q11 q13 mostró ser de gran utilidad para identificar los mecanismos genómicos y epigenéticos implicados en el SPW y el SA.

Utilidad de la técnica de MS-MLPA en el diagnóstico de los síndromes de Beckwith-Wiedemann y Silver-Russell / Usefulness of the MS-MLPA technique in the diagnosis of Beckwith-Wiedemann syndrome and Silver-Russell syndrome

Resumen Introducción: Las alteraciones epigenéticas y genómicas de la región improntada 11p15.5 producen crecimiento excesivo o deficiente, que se manifiesta como síndrome de Beckwith-Wiedemann o síndrome de Silver-Russell, respectivamente. Objetivo: Evaluar la técnica de análisis de metilación MLPA (MS-MLPA, methylation-specific multiplex ligation-dependent probe amplification) en el diagnóstico de los síndromes de Beckwith-Wiedemann y de Silver-Russell. Métodos: Se evaluó la metilación y las variantes de 11p15.5 en pacientes con diagnóstico clínico de síndrome de Beckwith-Wiedemann y síndrome de Silver-Russell mediante la técnica MS-MLPA en ADN de sangre periférica. Resultados: Se identificó disomía uniparental paterna y pérdida de metilación del IC2 materno en dos pacientes con síndrome de Beckwith-Wiedemann, quienes presentaron onfalocele y macroglosia, respectivamente. Se registró hipometilación paterna del IC1 en dos pacientes con síndrome de Silver-Russell de fenotipo clásico. Conclusiones: Se observó adecuada correlación genotipo-fenotipo con los defectos de metilación encontrados, lo que confirma la utilidad del MLPA como estudio de primera línea en pacientes con diagnóstico de síndrome de Beckwith-Wiedemann y síndrome de Silver-Russell.

Abstract Introduction: Epigenetic and genomic imprinting alterations of the 11p15.5 region cause excessive or deficient growth, which result in Beckwith-Wiedemann syndrome (BWS) or Silver-Russell syndrome (SRS), respectively. Objective: To evaluate the methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA) methylation analysis technique in the diagnosis of BWS and SRS. Methods: 11p15.5 methylation and variants were evaluated in patients with clinical diagnosis of BWS and SRS using the MS-MLPA technique in peripheral blood DNA. Results: Paternal uniparental disomy and loss of maternal IC2 methylation were identified in two patients with BWS who had omphalocele and macroglossia, respectively. Paternal IC1hypomethylation was recorded in two patients with SRS of classic phenotype. Conclusions: Adequate genotype-phenotype correlation was observed with the methylation defects that were identified, which confirms the usefulness of MLPA as a first-line study in patients diagnosed with BWS and SRS.