Frameshift Variant in ARID2 in a Chilean Individual with Coffin-Siris Syndrome Phenotype.

Coffin-Siris syndrome (CSS) is one of the several causes of intellectual disability (ID) and, since its first description, has posed diagnostic challenges given its variability and phenotypic overlap with other alterations of chromatin-remodeling-associated syndromes. It is genetically heterogeneous, and causative mutations are detected in less than 70% of cases. The different subtypes of the syndrome described to date are caused by mutations in genes that encode subunits of the SWI/SNF chromatin-remodeling complex, which plays an essential role in the regulation of gene expression during embryogenesis. Whole exome sequencing (WES) has allowed the identification of pathogenic mutations in these genes, including ARID2 . ARID2 is one of the primary components of the SWI/SNF complex and has been associated with ID and phenotypes similar to CSS for the first time in 2015. Fifteen published case reports have identified loss-of-function mutations, suggesting that the underlying pathogenic disease mechanism is haploinsufficiency of ARID2 . We herein presented the case of an 8-year-old Chilean girl with clinical suspicion of CSS, in whom a novel frameshift variant in ARID2 was identified by WES. She was the first reported case in Latin America to our knowledge and her phenotype displays the main clinical features suggestive of CSS described in other patients with ARID2 variants. However, she did not present behavioral abnormalities, a characteristic frequently reported in the majority of patients with ARID2 variants, and also had some features, such as sparse scalp hair, which is frequently reported as a manifestation of CSS, but is uncommon in this new group of patients.

Opportunities and challenges for newborn screening and early diagnosis of rare diseases in Latin America.

Rare diseases (RDs) cause considerable death and disability in Latin America. Still, there is no consensus on their definition across the region. Patients with RDs face a diagnostic odyssey to find a correct diagnosis, which may last many years and creates a burden for caregivers, healthcare systems, and society. These diagnostic delays have repercussions on the health and economic burden created by RDs and continue to represent an unmet medical need. This review analyzes barriers to the widespread adoption of newborn screening (NBS) programs and early diagnostic methods for RDs in Latin America and provides recommendations to achieve this critical objective. Increasing the adoption of NBS programs and promoting early diagnosis of RDs are the first steps to improving health outcomes for patients living with RDs. A coordinated, multistakeholder effort from leaders of patient organizations, government, industry, medical societies, academia, and healthcare services is required to increase the adoption of NBS programs. Patients' best interests should remain the guiding principle for decisions regarding NBS implementation and early diagnosis for RDs.

Consenso de la Rama de Genética de la Sociedad Chilena de Pediatría sobre las anomalías congénitas de mal pronóstico vital (ACMPV): Genetics Consensus Committee / Congenital anomalies of poor prognosis

Introducción: La rama de genética de la Sociedad Chilena de Pediatría, en relación con el proyecto de ley que regula la despenalización de la interrupción voluntaria del embarazo en 3 causales, centrándose en la segunda causal que considera al «embrión o feto que padezca una alteración estructural congénita o genética incompatible con la vida extrauterina¼, se reunió para discutir conforme a la evidencia científica qué anomalías congénitas (AC) podrían ser incluidas en el proyecto de ley. Metodología: Los expertos en genética clínica se centraron en 10 AC. Se efectuó revisión bibliográfica y una reunión extraordinaria para discutirla. Resultados: Se acordó no emplear el término «incompatible con la vida extrauterina¼, pues existen excepciones de sobrevidas más prolongadas y cambiar por «anomalía congénita de mal pronóstico vital (ACMPV)¼. Se evaluaron 10 AC: defectos graves de cierre del tubo neural: anencefalia, iniencefalia y craneorraquisquisis, hipoplasia pulmonar, feto acardio, ectopia cordis, triploidía no mosaico, complejo limb body wall, anomalía body stalk, trisomía 13, trisomía 18 y agenesia renal bilateral. Se analizaron los hallazgos sobre prevalencia, historia natural, métodos diagnósticos prenatales, sobrevida, casos descritos de sobrevida prolongada. Para catalogarlas como ACMPV se consideraron: sobrevida posnatal, existencia de tratamientos y evolución posterior e historia natural sin intervenciones. Conclusión: Las ACMPV incluidas serían: anencefalia, hipoplasia pulmonar severa, feto acardio, ectopia cordis cervical, triploidía no mosaico, complejo limb body wall, anomalía body stalk, trisomía 13 no mosaico, trisomía 18 no mosaico y agenesia renal bilateral. Se requiere para el diagnóstico que toda mujer gestante tenga acceso a evaluaciones ecográficas de anatomía fetal, y en ocasiones a resonancia magnética y estudios citogenéticos y moleculares.

Introduction: The Genetic Branch of the Chilean Society of Paediatrics, given the draft Law governing the decriminalisation of abortion on three grounds, focusing on the second ground, which considers the "embryo or foetus suffering from a congenital structural anomaly or a genetic disorder incompatible with life outside the womb", met to discuss the scientific evidence according to which congenital anomalies (CA) may be included in this draft law. Methodology: Experts in clinical genetics focused on 10 CA, reviewed the literature evidence, and met to discuss it. Results: It was agreed not to use the term "incompatible with life outside the womb", as there are exceptions and longer survivals, and change to "congenital anomaly of poor prognosis (CAPP)". Ten CA were evaluated: serious defects of neural tube closure: anencephaly, iniencephaly and craniorachischisis, pulmonary hypoplasia, acardiac foetus, ectopia cordis, non-mosaic triploidy, "limb body wall" complex, "body stalk" anomaly, trisomy 13, trisomy 18, and bilateral renal agenesis. Findings on the prevalence, natural history, prenatal diagnostic methods, survival, and reported cases of prolonged survival were analysed. Post-natal survival, existence of treatments, and outcomes, as well as natural history without intervention, were taken into account in classifying a CA as a CAPP. Conclusion: A CAPP would be: anencephaly, severe pulmonary hypoplasia, acardiac foetus, cervical ectopia cordis, non-mosaic triploidy, limb body wall complex, body stalk anomaly, non-mosaic trisomy 13, non-mosaic trisomy 18, and bilateral renal agenesis. For their diagnosis, it is required that all pregnant women have access to assessments by foetal anatomy ultrasound and occasionally MRI, and cytogenetic and molecular testing.

[Congenital anomalies of poor prognosis. Genetics Consensus Committee]. / Consenso de la Rama de Genética de la Sociedad Chilena de Pediatría sobre las anomalías congénitas de mal pronóstico vital (ACMPV).

INTRODUCTION: The Genetic Branch of the Chilean Society of Paediatrics, given the draft Law governing the decriminalisation of abortion on three grounds, focusing on the second ground, which considers the "embryo or foetus suffering from a congenital structural anomaly or a genetic disorder incompatible with life outside the womb", met to discuss the scientific evidence according to which congenital anomalies (CA) may be included in this draft law. METHODOLOGY: Experts in clinical genetics focused on 10 CA, reviewed the literature evidence, and met to discuss it. RESULTS: It was agreed not to use the term "incompatible with life outside the womb", as there are exceptions and longer survivals, and change to "congenital anomaly of poor prognosis (CAPP)". Ten CA were evaluated: serious defects of neural tube closure: anencephaly, iniencephaly and craniorachischisis, pulmonary hypoplasia, acardiac foetus, ectopia cordis, non-mosaic triploidy, "limb body wall" complex, "body stalk" anomaly, trisomy 13, trisomy 18, and bilateral renal agenesis. Findings on the prevalence, natural history, prenatal diagnostic methods, survival, and reported cases of prolonged survival were analysed. Post-natal survival, existence of treatments, and outcomes, as well as natural history without intervention, were taken into account in classifying a CA as a CAPP. CONCLUSION: A CAPP would be: anencephaly, severe pulmonary hypoplasia, acardiac foetus, cervical ectopia cordis, non-mosaic triploidy, limb body wall complex, body stalk anomaly, non-mosaic trisomy 13, non-mosaic trisomy 18, and bilateral renal agenesis. For their diagnosis, it is required that all pregnant women have access to assessments by foetal anatomy ultrasound and occasionally MRI, and cytogenetic and molecular testing.

Mutations in the heat-shock protein A9 (HSPA9) gene cause the EVEN-PLUS syndrome of congenital malformations and skeletal dysplasia.

We and others have reported mutations in LONP1, a gene coding for a mitochondrial chaperone and protease, as the cause of the human CODAS (cerebral, ocular, dental, auricular and skeletal) syndrome (MIM 600373). Here, we delineate a similar but distinct condition that shares the epiphyseal, vertebral and ocular changes of CODAS but also included severe microtia, nasal hypoplasia, and other malformations, and for which we propose the name of EVEN-PLUS syndrome for epiphyseal, vertebral, ear, nose, plus associated findings. In three individuals from two families, no mutation in LONP1 was found; instead, we found biallelic mutations in HSPA9, the gene that codes for mHSP70/mortalin, another highly conserved mitochondrial chaperone protein essential in mitochondrial protein import, folding, and degradation. The functional relationship between LONP1 and HSPA9 in mitochondrial protein chaperoning and the overlapping phenotypes of CODAS and EVEN-PLUS delineate a family of "mitochondrial chaperonopathies" and point to an unexplored role of mitochondrial chaperones in human embryonic morphogenesis.

Consideraciones sobre epigenética perinatal / Considerations about perinatal epigenetics

Se ha reconocido progresivamente que el riesgo de enfermedades del adulto, especialmente el síndrome metabólico, puede estar influenciado por exposiciones ambientales prenatales. El bajo peso de nacimiento, la recuperación del crecimiento durante la infancia, se asocian a un riesgo de obesidad del adulto, así como de enfermedad cardiovascular, y de efectos adversos en las funciones renal y cerebral. La exposición a obesidad materna, o el alto peso de nacimiento también representan un riesgo aumentado para obesidad de la infancia y la adultez. La exposición fetal a determinados químicos o contaminantes ambientales puede afectar la predisposición a enfermedades del adulto. Se aducen mecanismos de programación, que alteren el desarrollo de los órganos, respuestas a señales celulares, y modificaciones epigenéticas (es decir, control de la expresión génica sin modificación de la secuencia de ADN). El cuidado prenatal ha incorporado metas para optimizar la salud materna, fetal y neonatal para prevenir o reducir enfermedades del adulto. El embarazo, cuando el epigenoma está activamente programado es un tiempo vulnerable, es cuando las exposiciones tienen el efecto epigenético más profundo. Los profesionales de la salud que tratan y aconsejan a mujeres en edad reproductiva están en una posición privilegiada para protegerlas de alteraciones epigenéticas y de esa forma prevenir el impacto adverso en el feto en desarrollo que podría manifestarse a lo largo de su vida. El adulto sano es el resultado de una interacción exitosa entre el ambiente materno y el epigenoma fetal en desarrollo...

It has been gradually recognized that the risk of adult diseases, especially metabolic syndrome, can be influenced by prenatal environmental exposures. Low birth weight, growth recovery in childhood are associated with a risk of adult obesity and cardiovascular disease, and adverse effects on kidney and brain functions. Exposure to maternal obesity, or high birth weight also represent an increased risk for obesity in childhood and adulthood. Fetal exposure to certain chemicals or environmental pollutants may affect susceptibility to diseases in adults. Programming mechanisms that alter the development of organs, cellular responses to signals and epigenetic modifications (i.e., control of gene expression without changing the DNA sequence) are adduced. Prenatal care incorporated goals to optimize maternal, fetal, and neonatal health to prevent or reduce adult diseases. Pregnancy, when the epigenome is actively programmed, is a vulnerable time, and when exposures have the deepest epigenetic effect. Health professionals who treat and counsel women of childbearing age are in a privileged position to protect them from epigenetic alterations and thus prevent the adverse impact on the developing fetus that may manifest throughout his life. The healthy adult is the result of a successful interaction between maternal and fetal environment developing epigenome...

Raine syndrome: an overview.

Raine syndrome (RS) is a bone dysplasia characterised by generalised osteosclerosis with periosteal bone formation, characteristic face, and brain abnormalities [MIM # 259775]. Its prevalence is estimated to be < 1/1,000,000. Although it was originally thought always to be lethal, there have now been six reports of patients surviving into childhood and this phenotype is still being defined. The skeletal dysplasia predominantly affects craniofacial development explaining the severe proptosis, underdeveloped midface, depressed nasal bridge and short nose. The main radiological manifestation is a diffuse, marked osteosclerosis of the base of skull and long bones. Raine syndrome is caused by biallelic mutations in FAM20C, located on chromosome 7p22.3. This gene encodes a Golgi casein kinase, which phosphorylates serine residues of extracellular proteins involved in biomineralisation. Facial appearance and radiological findings allow the clinical diagnosis, and molecular testing of FAM20C can confirm this. Desmosterolosis and congenital cytomegalovirus infection may resemble Raine syndrome. If Raine syndrome is suspected prenatally the newborn should be admitted at a neonatal intensive care unit as significant respiratory distress is often present immediately after birth. We present here a review of the pertinent literature in clinical manifestations, molecular background, diagnosis and management.

Estudio cromosómico en abortos espontáneos / Chromosome study in spontaneous abortions

Aproximadamente 15 por ciento de todos los embarazos clínicos terminan en aborto espontáneo. La causa más frecuente de aborto espontáneo es una anomalía cromosómica fetal, tal como una trisomía autosómica, monosomía X y poliploidía. Desde mayo de 1991 hasta febrero de 2013 hemos realizado 2.416 estudios citogenéticos en restos de aborto en la Sección Citogenética del Laboratorio Clínico de Clínica Alemana de Santiago, Chile. Deseamos compartir la información sobre la distribución de los hallazgos en estos estudios, así como difundir la estrategia que hemos implementado desde febrero de 2010 con estudio de varias sondas de hibridación in situ con fluorescencia (FISH) en aquellos casos en que el cultivo no ha progresado, lo que permite entregar alguna información importante respecto a la presencia o ausencia de ciertas alteraciones cromosómicas en todos los estudios.

Approximately 15 percent of all clinical pregnancies end in spontaneous abortion. The most common cause of spontaneous abortion is a fetal chromosomal abnormality, such as an autosomal trisomy, monosomy X and polyploidy. From May 1991 until February 2013 we performed 2,416 cytogenetic studies in abortion tissues in the Cytogenetics Unit of the Clinical Laboratory Clínica Alemana de Santiago. We want to share information about the distribution of the findings in these studies, and want to disseminate the strategy we have implemented since February 2010 with multiple probes study of fluorescence in situ hybridization (FISH) in cases where the tissue culture had not progressed, allowing to provide some important information regarding the presence or absence of certain chromosomal abnormalities in all studies.

[Genetics of congenital deafness]. / Genética de la sordera congénita.

Congenital deafness is defined as the hearing loss which is present at birth and, consequently, before speech development. It is the most prevalent sensor neural disorder in developed countries, and its incidence is estimated between 1-3 children per 1,000 newborns, of which more than 50% are attributable to genetics causes. Deafness can be classified as syndromic or non-syndromic. In the first case, it is associated with outer ear malformations and/or systemic findings. More than 400 syndromes accompanied of deafness have been described, which represent about 30% of cases of congenital hearing loss. The remaining percentage corresponds to non-syndromic cases: 75-85% are autosomal recessive, 15-24% are autosomal dominant, and 1-2% are X-linked. The evaluation of a child with deafness requires a multidisciplinary collaboration among specialists, who must coordinate themselves and give information to the affected family. The aims of establishing a diagnosis are to predict other manifestations that may suggest some syndrome and to anticipate their management, as well as to perform genetic counseling to parents and affected individuals.

Cáncer hereditario de colon: Aportes del diagnóstico genético molecular / Molecular and genetic studies for hereditary colon cancer in two patients and their families

Background: About 30 percent of cases of colon cancer (CC) have a family history of CC, and only 5 percent are hereditary forms. Hereditary forms have an increased risk of CC and other tumors. Aim: To report the molecular and genetic study in two families with hereditary CC. Material and Methods: Molecular analysis of the adenomatous polyposis coli (APC) gene of familial adenomatous polyposis (FAP), was done in a patient with multiple benign polyps and his children. Molecular analysis was performed for MLH1 gene mutation of hereditary non-polyposis colon cancer (HNPCC) in an asymptomatic patient with family history of multiple cancers and his mother with a confrmed mutation in the MLH1 gene. Results: The patient with FAP had an insertion of 17 base pairs in exon 9 of the APC gene and two of his children had the same mutation. The patient with history of HNPCC did not have the family mutation on MLH1. Conclusions: In the case of FAP, molecular study was performed in his children since manifestations in carriers of the mutation may begin in childhood. If the second patient would have had the mutation, the study of his children could have been postponed until the age of 18, when the risk for CC is increased.

Marcadores genéticos en hipertensión esencial / Genetic markers in essential hypertension

Essential hypertension (HTA) is a multifactorial disease and in Chile, its prevalence is 33.7 percent. There is a genetic predisposition to develop hypertension, whose magnitude is approximately 30 to 50 percent. At present, some factors are known to increase the risk for cardiovascular disease, but widely accepted biomarkers for screening are missing. The frst studies that looked for candidate genes have focused on the reninangiotensin - aldosterone, aducina, adrenoreceptors ß, G protein subunits, G protein signaling regulators, kinases associated with G proteins and Rho kinases. Studies of DNA sequencing, search for polymorphisms and variants through single nucleotide polymorphisms, have been used to seek partnerships with complex or multifactorial diseases, like HTA. Examples of these are: components of collagen proteins, genes related to cell myocardial proteins belonging to cytochrome P450 and growth factors, among others. It is still unlikely to count in a near future with a universal marker. Most probably, a series of markers that confer susceptibility to a specifc individual will have to be used in prevention programs or personalized therapy.

[Molecular and genetic studies for hereditary colon cancer in two patients and their families]. / Cáncer hereditario de colon: aportes del diagnóstico genético molecular.

BACKGROUND: About 30% of cases of colon cancer (CC) have a family history of CC, and only 5% are hereditary forms. Hereditary forms have an increased risk of CC and other tumors. AIM: To report the molecular and genetic study in two families with hereditary CC. MATERIAL AND METHODS: Molecular analysis of the adenomatous polyposis coli (APC) gene of familial adenomatous polyposis (FAP), was done in a patient with multiple benign polyps and his children. Molecular analysis was performed for MLH1 gene mutation of hereditary non-polyposis colon cancer (HNPCC) in an asymptomatic patient with family history of multiple cancers and his mother with a confirmed mutation in the MLH1 gene. RESULTS: The patient with FAP had an insertion of 17 base pairs in exon 9 of the APC gene and two of his children had the same mutation. The patient with history of HNPCC did not have the family mutation on MLH1. CONCLUSIONS: In the case of FAP, molecular study was performed in his children since manifestations in carriers of the mutation may begin in childhood. If the second patient would have had the mutation, the study of his children could have been postponed until the age of 18, when the risk for CC is increased.

Hipertensión arterial infantil de origen monogénico / Hypertension Infant monogenic origin

La hipertensión arterial (HTA) es una patología frecuente en el adulto, en cambio, en pediatría es una patología subdiagnosticada y con una prevalencia del 1 al 2 por ciento. La hipertensión arterial de origen monogénico, representa a menos del 1 por ciento del total, sin embargo es importante su diagnóstico debido a que puede tener riesgo de recurrencia en la familia y ser transmitida a la descendencia. En esta revisión se describen los elementos de sospecha de HTA de origen monogénico, las causas principales, etiopatogenia molecular, clínica, técnicas diagnósticas, modos de herencia y tratamientos. Además se comenta el estado del arte sobre los genes candidatos en la HTA esencial. Conclusión: la HTA de origen monogénico es una señal de alerta de una condición subyacente, la historia personal, los antecedentes familiares y los exámenes de laboratorio, condicionarán el diagnósitco y el asesoramiento genérico para el paciente, como también una búsqueda dirigida en sus familiares.

[Services for the care and prevention of birth defects. Reduced report of a World Health Organization and March of Dimes Foundation meeting]. / Servicios para la atención y la prevención de defectos congénitos: Síntesis de una reunión de la Organización Mundial de la Salud y la Fundación March of Dimes.

On 17-19 May 2006, the World Health Organization (WHO) and the March of Dimes Birth Defects Foundation held a meeting in Geneva: The Management of Birth Defects and Haemoglobin Disorders. Meeting participants included 18 experts from developing and industrialized countries, including the author and nine staff from WHO Headquarters. The meeting had five goals: (A) ratify the data on the global toll of birth defects presented in the MOD Global Report; (B) agree upon a definition of terms; (C) develop a collaborative plan for strengthening care and prevention of birth defects; (D) develop a plan for strengthening care and prevention of haemoglobin disorders; and (E) determine how potential stakeholders could contribute to these efforts. The consensus for each of the goals were: a) Participants endorsed the estimates in the MOD Global Report, b) Participants concluded that the term "birth defect" is synonymous with the term "congenital disorder", whereas the term "congenital anomalies" should be avoided, c) Participants agreed that 70% of birth defects could be prevented, ameliorated or treated effectively, by the strengthening of medical genetic services, d) Participants agreed that efforts must be made to improve the control of hemoglobin disorders in developing countries, and e) Progress will require the combined efforts and political will of the WHO.

Servicios para la atención y la prevención de defectos congénitos: Síntesis de una reunión de la Organización Mundial de la Salud y la Fundación March of Dimes / Services for the care and prevention of birth defects. Reduced report of a World Health Organization and March of Dimes Foundation meeting

On 17-19 May 2006, the World Health Organization (WHO) and the March of Dimes Birth Defects Foundation held a meeting in Geneva: The Management of Birth Defects and Haemoglobin Disorders. Meeting participants included 18 experts from developing and industrialized countries, including the author and nine staff from WHO Headquarters. The meeting had five goals: (A) ratify the data on the global toll of birth defects presented in the MOD Global Report; (B) agree upon a definition of terms; (C) develop a collaborative plan for strengthening care and prevention of birth defects; (D) develop a plan for strengthening care and prevention of haemoglobin disorders; and (E) determine how potential stakeholders could contribute to these efforts. The consensus for each of the goals were: a) Participants endorsed the estimates in the MOD Global Report, b) Participants concluded that the term "birth defect" is synonymous with the term "congenital disorder", whereas the term "congenital anomalies" should be avoided, c) Participants agreed that 70 percent of birth defects could be prevented, ameliorated or treated effectively, by the strengthening of medical genetic services, d) Participants agreed that efforts must be made to improve the control of hemoglobin disorders in developing countries, and e) Progress will require the combined efforts and political will of the WHO.

[Maternal age and neural tube defects: evidence for a greater effect in spina bifida than in anencephaly]. / Edad materna y defectos del tubo neural: evidencia para un efecto mayor en espina bífida que anencefalia.

BACKGROUND: Recent evidence from birth order data suggest that maternal factors can differently influence anencephaly and spina bifida. AIM: To study the influence of maternal age on the risk for neural tube defects. MATERIAL AND METHODS: A meta-analysis of published data on neural tube defects (NTDs) was carried out to determine whether there is an increased risk to have a child with NTDs for younger and older mothers and if this risk differs depending on the type of NTD. All data available with information regarding the frequency of live births and NTDs cases by maternal age (five- or ten-year intervals) were included in the analysis. Effect sizes calculations were performed. RESULTS: The analysis supports the hypothesis that there is an increased risk of having an offspring with NTDs for mothers 40 years of age or older. However, this effect is stronger for spina bifida than for anencephaly. There is also evidence that mothers 19 years old or younger have a higher risk for having a child with spina bifida. CONCLUSIONS: Maternal age influences the risk of having an offspring with neural tube defects.

Edad materna y defectos del tubo neural: evidencia para un efecto mayor en espina bífida que anencefalia / Influence of maternal age on the risk for neural tube defects, a meta analysis

Background: Recent evidence from birth order data suggest that maternal factors can differently influence anencephaly and spina bifida. Aim: To study the influence of maternal age on the risk for neural tube defects. Material and methods: A meta-analysis of published data on neural tube defects (NTDs) was carried out to determine whether there is an increased risk to have a child with NTDs for younger and older mothers and if this risk differs depending on the type of NTD. All data available with information regarding the frequency of live births and NTDs cases by maternal age (five- or ten-year intervals) were included in the analysis. Effect sizes calculations were performed. Results: The analysis supports the hypothesis that there is an increased risk of having an offspring with NTDs for mothers 40 years of age or older. However, this effect is stronger for spina bifida than for anencephaly. There is also evidence that mothers 19 years old or younger have a higher risk for having a child with spina bifida. Conclusions: Maternal age influences the risk of having an offspring with neural tube defects.

[Mutational analysis of the muscle segment homeobox gene 1 (MSX1) in Chilean patients with cleft lip/palate]. / Análisis mutacional del gen Homeobox de segmento muscular 1 (MSX1) en chilenos con fisuras orales.

BACKGROUND: Mutations of the MSX1 gene may contribute to non-syndromic forms of cleft lip and/or cleft palate. AIM: To search for mutations of MSX1 coding regions, including one highly conserved non-coding region in the single intron, among Chilean patients with cleft lip/palate. PATIENTS AND METHODS: We studied 45 patients with cleft lip/palate and their parents. Oral mucosa samples were obtained with a swab. DNA was extracted and amplified by PCR. RESULTS: Two missense mutations (G16D and G34A) were identified in this study that may be useful for future admixture studies. The G16D mutation appears to disrupt a possible splicing site and may contribute to clefting in this population. CONCLUSIONS: Rare MSX1 mutations are found in some cases of cleft lip and/or cleft palate but others remain to be found most likely in other regulatory regions of the gene.

Análisis mutacional del gen Homeobox de segmento muscular 1 (MSX1) en chilenos con fisuras orales / Mutational analysis of the muscle segment homeobox gene 1 (MSX1) in Chilean patients with cleft lip/palate

Background: Mutations of the MSX1 gene may contribute to nonsyndromic forms of cleft lip and/or cleft palate. Aim: To search for mutations of MSX1 coding regions, including one highly conserved non-coding region in the single intron, among Chilean patients with cleft lip/palate. Patients and Methods: We studied 45 patients with cleft lip/palate and their parents. Oral mucosa samples were obtained with a swab. DNA was extracted and amplified by PCR. Results: Two missense mutations (G16D and G34A) were identified in this study that may be useful for future admixture studies. The G16D mutation appears to disrupt a possible splicing site and may contribute to clefting in this population. Conclusions: Rare MSX1 mutations are found in some cases of cleft lip and/or cleft palate but others remain to be found most likely in other regulatory regions of the gene.