Frequency of chromosome 22q11.2 deletion among newborns with non-syndromic congenital heart defects from western Mexico.

BACKGROUND: Congenital heart defects (CHD) are among the most frequent manifestations of 22q11.2 deletion syndrome. Although we found relatively few studies aimed at specifically detecting 22q11.2 deletion in newborns (NB) with CHD, none of them has been performed in Mexico. METHODS: We conducted a prospective hospital-based study from January 2017 to March 2021 in the Genetics and Pediatric Cardiology Services of the Hospital Civil de Guadalajara Dr. Juan I. Menchaca (Guadalajara, Mexico). All consecutive NBs identified with any non-syndromic major CHD confirmed by echocardiography were eligible to participate. A total of 98 NBs were included, 51 males and 47 females. Fluorescence in situ hybridization (FISH) analysis was conducted to search for deletion of chromosome 22q11.2 in interphase nuclei of standard lymphocyte cultures. RESULTS: We found eight patients (8.2%) with CHD and the 22q11.2 deletion, all of them with conotruncal defects, particularly of the truncus arteriosus (p = 0.013), tetralogy of Fallot (p = 0.024), and pulmonary atresia with ventricular septal defect (p = 0.031) subtypes. With de exception of one infant with hypocalcemia and another with hypocalcemia and thymic aplasia, the diagnosis of 22q11.2 deletion was not clinically suspected in the other patients. CONCLUSIONS: Our results confirm the importance of excluding the presence of the 22q11.2 deletion in every NB with CHDs, particularly of the conotruncal subtype, even in the absence of other manifestations.

INTRODUCCIÓN: Las cardiopatías congénitas (CC) son una de las manifestaciones más frecuentes del síndrome de deleción 22q11.2. A pesar de que existen relativamente pocos estudios dirigidos a detectar específicamente la deleción 22q11.2 en recién nacidos (RN) con CC, ninguno de ellos ha sido realizado en México. MÉTODOS: Se realizó un estudio prospectivo de base hospitalaria desde enero de 2017 hasta marzo de 2021 en los Servicios de Genética y Cardiología Pediátrica del Hospital Civil de Guadalajara Dr. Juan I. Menchaca (Guadalajara, México). Todos los RN consecutivos identificados con cualquier tipo de CC mayor no sindrómica confirmada por ecocardiografía fueron elegibles para participar. Se incluyeron 98 recién nacidos, 51 de sexo masculino y 47 de sexo femenino. Mediante el análisis de hibridación fluorescente in situ (FISH, por sus siglas en inglés) se realizó la búsqueda de la deleción del cromosoma 22q11.2 en núcleos en interfase de cultivos de linfocitos estándar. RESULTADOS: Se encontraron ocho pacientes (8.2%) con CC y la deleción 22q11.2, todos ellos con defectos conotruncales, particularmente de los subtipos tronco arterioso (p = 0.013), tetralogía de Fallot (p = 0.024) y atresia pulmonar con comunicación interventricular (p = 0.031). Con excepción de un lactante con hipocalcemia y otro con hipocalcemia y aplasia tímica, el diagnóstico de deleción 22q11.2 no se sospechó clínicamente en los demás pacientes. CONCLUSIONES: Los resultados de este trabajo confirman la importancia de excluir la presencia de la deleción 22q11.2 en todos los RN con CC, particularmente del subtipo conotruncal, incluso en ausencia de otras manifestaciones.

Frequency of chromosome 22q11.2 deletion among newborns with non-syndromic congenital heart defects from western Mexico / Frecuencia de la deleción del cromosoma 22q11.2 en recién nacidos con cardiopatías congénitas no sindrómicas del occidente de México

Abstract Background: Congenital heart defects (CHD) are among the most frequent manifestations of 22q11.2 deletion syndrome. Although we found relatively few studies aimed at specifically detecting 22q11.2 deletion in newborns (NB) with CHD, none of them has been performed in Mexico. Methods: We conducted a prospective hospital-based study from January 2017 to March 2021 in the Genetics and Pediatric Cardiology Services of the Hospital Civil de Guadalajara Dr. Juan I. Menchaca (Guadalajara, Mexico). All consecutive NBs identified with any non-syndromic major CHD confirmed by echocardiography were eligible to participate. A total of 98 NBs were included, 51 males and 47 females. Fluorescence in situ hybridization (FISH) analysis was conducted to search for deletion of chromosome 22q11.2 in interphase nuclei of standard lymphocyte cultures. Results: We found eight patients (8.2%) with CHD and the 22q11.2 deletion, all of them with conotruncal defects, particularly of the truncus arteriosus (p = 0.013), tetralogy of Fallot (p = 0.024), and pulmonary atresia with ventricular septal defect (p = 0.031) subtypes. With de exception of one infant with hypocalcemia and another with hypocalcemia and thymic aplasia, the diagnosis of 22q11.2 deletion was not clinically suspected in the other patients. Conclusions: Our results confirm the importance of excluding the presence of the 22q11.2 deletion in every NB with CHDs, particularly of the conotruncal subtype, even in the absence of other manifestations.

Resumen Introducción: Las cardiopatías congénitas (CC) son una de las manifestaciones más frecuentes del síndrome de deleción 22q11.2. A pesar de que existen relativamente pocos estudios dirigidos a detectar específicamente la deleción 22q11.2 en recién nacidos (RN) con CC, ninguno de ellos ha sido realizado en México. Métodos: Se realizó un estudio prospectivo de base hospitalaria desde enero de 2017 hasta marzo de 2021 en los Servicios de Genética y Cardiología Pediátrica del Hospital Civil de Guadalajara Dr. Juan I. Menchaca (Guadalajara, México). Todos los RN consecutivos identificados con cualquier tipo de CC mayor no sindrómica confirmada por ecocardiografía fueron elegibles para participar. Se incluyeron 98 recién nacidos, 51 de sexo masculino y 47 de sexo femenino. Mediante el análisis de hibridación fluorescente in situ (FISH, por sus siglas en inglés) se realizó la búsqueda de la deleción del cromosoma 22q11.2 en núcleos en interfase de cultivos de linfocitos estándar. Resultados: Se encontraron ocho pacientes (8.2%) con CC y la deleción 22q11.2, todos ellos con defectos conotruncales, particularmente de los subtipos tronco arterioso (p = 0.013), tetralogía de Fallot (p = 0.024) y atresia pulmonar con comunicación interventricular (p = 0.031). Con excepción de un lactante con hipocalcemia y otro con hipocalcemia y aplasia tímica, el diagnóstico de deleción 22q11.2 no se sospechó clínicamente en los demás pacientes. Conclusiones: Los resultados de este trabajo confirman la importancia de excluir la presencia de la deleción 22q11.2 en todos los RN con CC, particularmente del subtipo conotruncal, incluso en ausencia de otras manifestaciones.

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.

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.

Family history of thyroid disease and risk of congenital hypothyroidism in neonates with Down síndrome.

INTRODUCTION: Family history of thyroid disease (FHTD) constitutes a possible risk factor for congenital hypothyroidism (CH) in the general population; however, FHTD possible relationship with CH in subjects with Down syndrome (DS) has not yet been explored. OBJECTIVE: To determine whether FHTD is associated with an increased incidence of CH in neonates with DS. METHOD: Hospital-based case-control study in 220 neonates with DS. Thyroid function tests of 37 infants with DS and positive FHTD (cases) were compared with those of 183 newborns with DS without FHTD (control group). Data were analyzed using multivariate logistic regression analysis and adjusted odds ratios (aORs) with their respective 95 % confidence intervals (CI) were calculated. RESULTS: Nine newborns with DS in our sample had CH (4.1 %). In the multivariate analysis, FHTD showed an association with CH in neonates with DS (aOR = 8.3, 95 % CI: 2.0-34.3), particularly in males (aOR = 9.0, 95 % CI: 1.6-49.6). In contrast, newborns with DS without FHTD were less likely to suffer from CH (aOR = 0.4, 95 % CI: 0.1-0.8). CONCLUSIONS: Newborns with DS and FHTD have an eight-fold higher risk for CH, particularly when the index case is male. FHTD detailed evaluation can be an easy and accessible strategy to identify those newborns with DS at higher risk for CH.

INTRODUCCIÓN: La historia familiar de enfermedad tiroidea (HFET) como factor de riesgo para hipotiroidismo congénito (HC), en síndrome de Down (SD) aún no ha sido explorada. OBJETIVO: Determinar si la HFET está asociada a mayor riesgo de HC en neonatos con SD. MÉTODO: Estudio de casos y controles en 220 neonatos con SD. Se compararon las pruebas de función tiroidea (PFT) de 37 con SD e HFET (casos), frente a las PFT de 183 recién nacidos con SD sin HFET (grupo de referencia). Se realizó análisis de regresión logística multivariante y se calculó la razón de momios (RM) y sus respectivos intervalos de confianza del 95 % (IC 95 %). RESULTADOS: Nueve casos HC (4.1 %). El HC mostró asociación con la HFET (RMa = 8.3, IC 95 %: 2.0-34.3), particularmente en los varones (RMa = 9.0, IC 95 %: 1.6-49.6). La ausencia de HFET tuvo una RM de protección para HC (RMa = 0.4, IC 95 %: 0.1-0.8). CONCLUSIONES: La HFET puede es una estrategia fácil y accesible para identificar pacientes con SD con mayor riesgo de HC.

Historia familiar de enfermedad tiroidea y riesgo de hipotiroidismo congénito en neonatos con síndrome de Down / Family history of thyroid disease and risk of congenital hypothyroidism in neonates with Down syndrome

Resumen Introducción: La historia familiar de enfermedad tiroidea (HFET) como factor de riesgo para hipotiroidismo congénito (HC), en síndrome de Down (SD) aún no ha sido explorada. Objetivo: Determinar si la HFET está asociada a mayor riesgo de HC en neonatos con SD. Método: Estudio de casos y controles en 220 neonatos con SD. Se compararon las pruebas de función tiroidea (PFT) de 37 con SD e HFET (casos), frente a las PFT de 183 recién nacidos con SD sin HFET (grupo de referencia). Se realizó análisis de regresión logística multivariante y se calculó la razón de momios (RM) y sus respectivos intervalos de confianza del 95 % (IC 95 %). Resultados: Nueve casos HC (4.1 %). El HC mostró asociación con la HFET (RMa = 8.3, IC 95 %: 2.0-34.3), particularmente en los varones (RMa = 9.0, IC 95 %: 1.6-49.6). La ausencia de HFET tuvo una RM de protección para HC (RMa = 0.4, IC 95 %: 0.1-0.8). Conclusiones: La HFET puede es una estrategia fácil y accesible para identificar pacientes con SD con mayor riesgo de HC.

Abstract Introduction: Family history of thyroid disease (FHTD) as risk factor for congenital hypothyroidism (CH) in patients with Down syndrome (DS) has not yet been explored. Objective: To determine whether FHTD is associated with an increased risk for CH in DS. Method: Case-control study in 220 neonates with DS. Thyroid function tests of 37 infants with DS and FHTD (cases) were compared with those of 183 DS newborns without FHTD (reference group). Data were analyzed using multivariate logistic regression analysis and adjusted odds ratios (aORs) with their respective 95 % confidence intervals (CI) were calculated. Results: Nine newborns with DS in our sample had CH (4.1 %). FHTD showed an association with CH in neonates with DS (aOR = 8.3, 95 % CI: 2.0-34.3), particularly in males (aOR = 9.0, 95 % CI: 1.6-49.6). In contrast, newborns with DS without FHTD were less likely to suffer from CH (aOR = 0.4, 95 % CI: 0.1-0.8). Conclusions: FHTD detailed evaluation can be an easy and accessible strategy to identify those newborns with DS at higher risk for CH.

Hipertricosis cervical anterior: caso dínico / Anterior cervical hypertrichosis: case report

La hipertricosis cervical anterior no sindrómica (OMIM N° 600457) es un desorden genético caracterizado por un parche de pelo a nivel de la prominencia laríngea. Se presenta a un niño de 12 años de edad con hipertricosis cervical anterior e hipertricosis generalizada leve, sin alteraciones neurológicas, oftalmológicas ni esqueléticas, en seguimiento clínico por un lapso de 10 años.

The non-syndromic anterior cervical hypertrichosis (OMIM N° 600457) is a genetic disorder characterized by a patch of hair at the level of the laryngeal prominence. We present a 12-year-old boy with anterior cervical hypertrichosis and mild generalized hypertrichosis. He has no neurological, ophthalmological or skeletal anomalies. The clinical follow up is 10 years.

[Anterior cervical hypertrichosis: case report]. / Hipertricosis cervical anterior: caso dínico.

The non-syndromic anterior cervical hypertrichosis (OMIM N° 600457) is a genetic disorder characterized by a patch of hair at the level of the laryngeal prominence. We present a 12-year-old boy with anterior cervical hypertrichosis and mild generalized hypertrichosis. He has no neurological, ophthalmological or skeletal anomalies. The clinical follow up is 10 years.

La hipertricosis cervical anterior no sindrómica (OMIM N° 600457) es un desorden genético caracterizado por un parche de pelo a nivel de la prominencia laríngea. Se presenta a un niño de 12 años de edad con hipertricosis cervical anterior e hipertricosis generalizada leve, sin alteraciones neurológicas, oftalmológicas ni esqueléticas, en seguimiento clínico por un lapso de 10 años.

Pediatric donor cell leukemia after allogeneic hematopoietic stem cell transplantation in AML patient from related donor.

Here we present a male patient with acute myeloid leukemia (AML) initially diagnosed as M5 and with karyotype 46,XY. After induction therapy, he underwent a HLA-matched allogeneic hematopoietic stem cell transplantation, and six years later he relapsed as AML M1 with an abnormal karyotype //47,XX,+10[2]/47,XX,+11[3]/48,XX,+10,+11[2]/46,XX[13]. Based on this, we tested the possibility of donor cell origin by FISH and molecular STR analysis. We found no evidence of Y chromosome presence by FISH and STR analysis consistent with the success of the allogeneic hematopoietic stem cell transplantation from the female donor. FISH studies confirmed trisomies and no evidence of MLL translocation either p53 or ATM deletion. Additionally 28 fusion common leukemia transcripts were evaluated by multiplex reverse transcriptase-polymerase chain reaction assay and were not rearranged. STR analysis showed a complete donor chimerism. Thus, donor cell leukemia (DCL) was concluded, being essential the use of cytological and molecular approaches. Pediatric DCL is uncommon, our patient seems to be the sixth case and additionally it presented a late donor cell leukemia appearance. Different extrinsic and intrinsic mechanisms have been considered to explain this uncommon finding as well as the implications to the patient.

DNA damage in mouse lymphocytes exposed to curcumin and copper.

Dietary polyphenolics, such as curcumin, have shown antioxidant and anti-inflammatory effects. Some antioxidants cause DNA strand breaks in excess of transition metal ions, such as copper. The aim of this study was to evaluate the in vitro effect of curcumin in the presence of increasing concentrations of copper to induce DNA damage in murine leukocytes by the comet assay. Balb-C mouse lymphocytes were exposed to 50 microM curcumin and various concentrations of copper (10 microM, 100 microM and 200 microM). Cellular DNA damage was detected by means of the alkaline comet assay. Our results show that 50 microM curcumin in the presence of 100-200 microM copper induced DNA damage in murine lymphocytes. Curcumin did not inhibit the oxidative DNA damage caused by 50 microM H2O2 in mouse lymphocytes. Moreover, 50 microM curcumin alone was capable of inducing DNA strand breaks under the tested conditions. The increased DNA damage by 50 mM curcumin was observed in the presence of various concentrations of copper, as detected by the alkaline comet assay.

Cell cycle and centromere FISH studies in premature centromere division.

BACKGROUND: Mitotic configurations consistent in split centromeres and splayed chromatids in all or most of the chromosomes or premature centromere division (PCD) have been described in three categories. (1) Low frequency of PCD observed in colchicines-treated lymphocyte cultures from normal individuals. (2) High frequency of PCD with mosaic variegated aneuploidy. (3) High frequency of PCD as a sole chromosome abnormality observed in individuals with no recognizable clinical pattern. We report four members of a family with the third category of PCD. METHODS: Cell cycle duration assessed by average generation time using differential sister chromatid stain analysis and FISH studies of DNA centromere sequences in PCD individuals, are included and compared with previously reported PCD individuals from 9 families. RESULTS: We observed PCD in colchicine-treated cultures from the propositus, his father, and two paternal aunts but not in his mother and four other paternal and maternal family members, as well as in untreated cultures from the propositus and his father. We observed cytological evidence of active centromeres by Cd stain. Significative cell cycle time reduction in anaphases of PCD individuals (average generation time of 21.8 h;SD 0.4) with respect to individuals without PCD (average generation time of 31.8 h;SD 3.9) was observed (P < 0.005, Student t-test for independent samples). Increased cell proliferation kinetics was observed in anaphasic cells of individuals with PCD, by differential sister chromatid stain analysis. FISH studies revealed the presence of alpha satellite DNA from chromosomes 1, 13, 21/18, X, all centromeres, and CENP-B box sequences in metaphasic and anaphasic cells from PCD individuals. CONCLUSION: This report examines evidences of a functional relationship between PCD and cell cycle impairment. It seems that essential centromere integrity is present in these cases.