[Mitochondrial DNA depletion syndrome-13: a case with an unusual onset]. / Síndrome de depleción de ADN mitocondrial tipo 13: un caso con un inicio poco común.

TITLE: Síndrome de depleción de ADN mitocondrial tipo 13: un caso con un inicio poco común.

[Schinzel-Giedion syndrome: a new mutation in SETBP1]. / Síndrome Schinzel-Giedion: nueva mutación en SETBP1.

Schinzel-Giedion syndrome (SGS) (#MIM 269150) is a rare genetic disorder characterized by very marked craniofacial dysmorphism, multiple congenital anomalies and severe intellectual disability. Most affected patients die in early childhood. SETBP1 was identified as the causative gene, but a limited number of patients with molecular confirmation have been reported to date. The case is reported of a 4 and a half year-old male patient, affected by SGS. SETBP1 sequencing analysis revealed the presence of a non-previously described mutation: c.2608G>T (p.Gly870Cys). The clinical features and differential diagnosis of this rare condition are reviewed. Dysmorphic features are strongly suggestive of SGS. Its clinical recognition is essential to enable an early diagnosis, a proper follow-up, and to provide the family with genetic counseling. To date, this is the seventeenth SGS patient published with SETBP1 mutation, and the first in Spain, helping to widen clinical and molecular knowledge of the disease.

A compound heterozygous mutation in the EDAR gene in a Spanish family with autosomal recessive hypohidrotic ectodermal dysplasia.

Hypohidrotic ectodermal dysplasia (HED) is a genetic disorder characterised by sparse hair, lack of sweat glands and malformation of teeth. The X-linked form of the disease, caused by mutations in the EDA gene, represents the majority of HED cases. Autosomal forms result from mutations in either the EDAR or the EDARADD gene. The X-linked and autosomal forms are phenotypically indistinguishable. For the purpose of genetic counselling, it is, therefore, important to know which gene is involved. In this study, we ascertained a Spanish family demonstrating the autosomal recessive form of HED. Affected individuals in the family showed the characteristic features of HED, including fine and sparse scalp hair, sparse eyebrows and eyelashes, periorbital hyperpigmentation, prominent lips, hypodontia and conical teeth, reduced sweating, and dry and thin skin. Sequence analysis of the EDAR gene revealed a novel compound heterozygous mutation [c.52-2A>G; c.212G>A (p.Cys71Tyr)]. Our finding extends the body of evidence that supports the significance of the EDAR signalling pathway in the ectodermal morphogenesis.

Realización e interpretación del árbol genealógico / Making and interpretation of the family tree

El árbol genealógico es una representación gráfica de la historia familiar, donde se utilizan unos símbolos estándar para que sea universal y puede ser fácilmente interpretado por otros profesionales. Es una herramienta básica y fundamental en cualquier especialidad médica y, por supuesto, en genética. La elaboración de un árbol genealógico permite identificar en muchos casos un patrón de herencia monogénico, que va a ser de gran ayuda en la orientación diagnostica de muchos pacientes. En este artículo se repasan las normas de realización de un árbol genealógico, así como su interpretación, basándonos en los distintos modelos de herencia mendeliana, teniendo en cuenta la existencia de factores que modifican su penetrancia y/o expresividad que pueden complicar su interpretación. También se incluyen algunos tipos de herencia no mendeliana acompañados de ejemplos ilustrativos (AU)

A pedigree is a graphical representation of a family history. The use of clear and consistent symbols allows genetic information to be set out clearly and provides and unambiguous and permanent record of the genetic information in a family. It is a basic tool in medicine, and specially in genetics. A pedigree will allow the clinician to identify a pattern of transmission of the disorder in the family which will be very helpful in order to give a diagnostic approach. In this article we review the main symbols used in constructing pedigrees, and were summarize the different patterns of transmission of mendelian disorders. Nonmendelian inheritance patterns and other modifier factors of mendelian disorders which can confuse the interpretation of pedigrees are also discussed (AU)

[Review of 22 patients with 22q11.2 deletion syndrome: phenotype spectrum]. / Revisión de 22 casos de deleción 22q11.2: espectro fenotípico.

INTRODUCTION: The 22q11.2 deletion syndrome is a contiguous gene deletion syndrome with an incidence rate of 1/4,000-6,000 live births. The most specific clinical features are: congenital conotruncal heart diseases, palate anomalies, hypocalcaemia, immunity and learning problems, and a characteristic facial phenotype. The objective of this work is to review the presenting phenotype and clinical features of children with 22q11.2 deletion syndrome as a guide for early diagnosis. PATIENTS AND METHODS: Retrospective study of 22 patients with 22q11.2 deletion syndrome diagnosed at our hospital in the time period 2004-2007. Variables analyzed: incidence, sex, age at diagnosis, presenting phenotype, clinical features, positive family history, mortality and natural history. RESULTS: From a total of 22 patients, 63 % were males, and the median age at diagnosis was of 4.5 years. Presenting pheno-type: congenital heart disease, milestones delay, velopharyngeal incompetence, hypocalcaemia, and mental retardation/psychiatric disturbances. CLINICAL FEATURES: congenital heart disease (84 %), velopharyngeal incompetence (47 %), milestones delay and learning disabilities (79 %). All of the deletions were de novo, except in one case where the deletion was present as mosaicism in the father. Three patients died, due to congenital heart disease. CONCLUSIONS: Clinical expression is widely variable, although a characteristic phenotype exists. Patients with heart disease are diagnosed earlier than other patients with unusual presenting phenotype such as congenital dysphagia. It is important to recognize less common phenotypes at early ages in order to provide multidisciplinary monitoring and accurate genetic counselling.

Revisión de 22 casos de deleción 22q11.2: espectro fenotípico / Review of 22 patients with 22q11.2 deletion syndrome: phenotype spectrum

Introducción: El síndrome de deleción 22q11.2 es un síndrome de genes contiguos con una incidencia de un caso por cada 4.000-6.000 recién nacidos. Posee una amplia variabilidad clínica y sus características clínicas más frecuentes son cardiopatía conotruncal, anomalías palatinas, hipocalcemia, problemas de inmunidad y de aprendizaje, y un fenotipo facial característico. El objetivo de este estudio es revisar las formas de presentación y las manifestaciones clínicas de los niños con deleción 22q11.2 como guía para su diagnóstico precoz. Pacientes y métodos: Estudio retrospectivo de 22 casos de deleción 22q11.2 diagnosticados en nuestro hospital entre los años 2004 y 2007, en que se analizan las siguientes variables: incidencia, sexo, edad en el momento del diagnóstico, forma de presentación, características clínicas, antecedentes familiares, mortalidad y evolución. Resultados: De los 22 pacientes, el 63 % fueron varones y la edad media en el momento de realizar el diagnóstico fue de 4,5 años. Las formas de presentación fueron cardiopatía, retraso psicomotor, insuficiencia velopalatina, hipocalcemia y retraso mental o alteraciones psiquiátricas. Las principales manifestaciones clínicas fueron cardiopatía (84 %), insuficiencia velopalatina (47 %), retraso psicomotor y problemas de aprendizaje (79 %). Todos los casos fueron deleciones de novo, salvo un caso en el que se identificó la deleción "en mosaico" en el padre. Fallecieron 3 pacientes a causa de cardiopatía. Conclusiones: La expresión clínica es muy variable, aunque existe un fenotipo característico. Los niños con cardiopatía conotruncal son diagnosticados más tempranamente, pero en otras formas de presentación, como la disfagia congénita, el diagnóstico se retrasa más. Es necesario tener en cuenta las formas de presentación menos habituales para identificar en edades tempranas a estos pacientes y proporcionarles una atención multidisciplinaria temprana y un asesoramiento genético familiar adecuado (AU)

Introduction: The 22q11.2 deletion syndrome is a contiguous gene deletion syndrome with an incidence rate of 1/4,000-6,000 live births. The most specific clinical features are: congenital conotruncal heart diseases, palate anomalies, hypocalcaemia, immunity and learning problems, and a characteristic facial phenotype. The objective of this work is to review the presenting phenotype and clinical features of children with 22q11.2 deletion syndrome as a guide for early diagnosis. Patients and methods: Retrospective study of 22 patients with 22q11.2 deletion syndrome diagnosed at our hospital in the time period 2004-2007. Variables analyzed: incidence, sex, age at diagnosis, presenting phenotype, clinical features, positive family history, mortality and natural history. Results: From a total of 22 patients, 63 % were males, and the median age at diagnosis was of 4.5 years. Presenting pheno-type: congenital heart disease, milestones delay, velopharyngeal incompetence, hypocalcaemia, and mental retardation/psychiatric disturbances. Clinical features: congenital heart disease (84 %), velopharyngeal incompetence (47 %), milestones delay and learning disabilities (79 %). All of the deletions were de novo, except in one case where the deletion was present as mosaicism in the father. Three patients died, due to congenital heart disease. Conclusions: Clinical expression is widely variable, although a characteristic phenotype exists. Patients with heart disease are diagnosed earlier than other patients with unusual presenting phenotype such as congenital dysphagia. It is important to recognize less common phenotypes at early ages in order to provide multidisciplinary monitoring and accurate genetic counseling (AU)