Mosaicismo de trisomía 9: caso de larga supervivencia / Mosaic trisomy 9: report of a new case with a long-term survival

Introducción: La trisomía 9 es una aneuploidía infrecuente y, por tanto, difícil de sospechar. Objetivo: Comunicar un nuevo caso de mosaicismo de trisomía 9, de larga supervivencia, para contribuir al mejor conocimiento de sus características clínicas y pronóstico. Caso clínico: Primera hija de padres sanos. Retraso de crecimiento intrauterino asimétrico y oligohidramnios. Nace a las 34 semanas con 1.478 g de peso, depresión respiratoria y fenotipo anómalo: dolicocefalia; hipotelorismo, microftalmia, hendiduras palpebrales pequeñas; nariz de base ancha y punta en bulbo; micrognatia; orejas de implantación baja, y anomalías en las manos y los pies. Ausencia de malformaciones en los órganos internos. Cariotipo: normal (46,XX). A los 17 meses, ante el retraso psicomotor evidente y las alteraciones descritas se realiza un segundo cariotipo convencional insistiendo en el análisis de un mayor número de células. Se halla un mosaicismo de trisomía 9 (46,XX/47,XX, 1 9). Como dato fenotípico curioso, a los 24 meses aparece un incisivo único superior medial, no descrito antes en otros casos de trisomía 9. Actualmente, tiene 4 años, un retraso mental profundo y ninguna otra complicación. Comentarios: Destaca la mayor dificultad diagnóstica de los mosaicismos; por lo que se debe insistir en el análisis de un número suficiente de células al estudiar el cariotipo. Además, es importante su diagnóstico en sujetos con anomalías fenotípicas, para dar información correcta a los padres en orden a su pronóstico y a la futura descendencia (AU)

Introduction: Trisomy 9 is an uncommon chromosome abnormality that may be seen in a mosaic or non-mosaic state. Objective: To better define the phenotype and prognosis of this disorder we report a new case of mosaic trisomy 9 with a long-term survival. Clinical report: We present the case of a female patient, born from the first pregnancy of a healthy couple. Fetal ultrasounds disclosed intrauterine growth retardation and oligohydramnios. Cesarean section was performed in the 34th week. Birth weight was 1,478 g. Neonatal examination showed: dolichocephaly; hypotelorism, microphthalmia, short palpebral fissures; broad-based nose with bulbous tip; micrognathia; low-set malformed ears; abnormal hands and feet; no other malformations. The initial karyotype determination was normal (46,XX). At 17 months of age, a second karyotype was requested because the patient developed severe psychomotor retardation. Chromosome analysis showed mosaic trisomy 9 (46,XX/47,XX, 1 9). Six months later, a single upper central incisor was noted. To our knowledge, this feature has not been reported previously in the trisomy 9. The patient is now 4 years old. She shows severe psychomotor retardation, but no other complications. Comments: It is important to be aware of the possibility that mosaicism may exist in a patient with normal blood karyotype and abnormal phenotype. We conclude that a great number of cells is needed in order to obtain a correct karyotype diagnosis. Correct diagnosis is essential to define the prognosis and provide accurate genetic counseling (AU)

Hipertricosis localizada y mosaicismo pigmentario tipo Ito (hipomelanosis de Ito) / Localized hypertrichosis and pigmentary mosaicism of Ito (hypomelanosis of Ito)

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Nevos de Spitz agrupados sobre una mácula hiperpigmentada / Agminated Spitz nevi on a hyperpigmented macule

Presentamos el caso de un niño de 2 años con múltiples nevos de Spitz agrupados sobre una mácula hiperpigmentada, que seguía un patrón en cuadrante. Los nevos de Spitz múltiples son raros y pueden presentarse de forma diseminada o agrupada. Un tercio de las lesiones agrupadas puede aparecer sobre una mácula hiperpigmentada

We present the case of a 2-year-old boy with multiple Spitz nevi clustered on a hyperpigmented macule that obeyed a quadrant distribution. Multiple Spitz nevi are rare and can be disseminated or clustered. A third of the cases of agminated lesions appear on hyperpigmented macules

Hiperpigmentación congénita siguiendo las líneas de Blaschko / Congenital hyperpigmentation along the lines of Blaschko

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Lesiones cutáneas hipopigmentadas y facies particular / Hypopigmented skin lesions and coarse facies

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Interpretación y expresión clínica de mosaicos cromosómicos / No disponible

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Nevo poroqueratósico de los ostios y ductos ecrinos / Porokeratotic eccrine ostial and dermal duct nevus

Se considera que el nevo poroqueratósico de los ostios y ductos ecrinos (NPODE) es un hamartoma del conducto sudoríparo. Presentamos el caso de una niña de un mes de edad que presentaba desde el nacimiento una erupción distribuida según las líneas de Blaschko en las extremidades y el tronco, con clara afectación palmoplantar. No se acompañaba de ningún otro defecto congénito y la paciente presentaba un desarrollo normal. La biopsia de una de las lesiones mostró los hallazgos típicos del nevo poroqueratósico de los ostios y ductos ecrinos. La anatomía patológica y las técnicas de inmunohistoquímica en este trastorno parecen revelar que la invaginación epidérmica en donde se halla la lámina paraqueratósica (similar a una lamela cornoide) es atravesada por un acrosiringio aparentemente normal. Dada la distribución de las lesiones y su aparición esporádica, el trastorno parece representar un mosaicismo genético (AU)

Estudio de mosaicismo y seudomosaicismo en diagnóstico prenatal citogenético. Experiencias en Ciudad de La Habana / Mosaicism and pseudomosaicism in prenatal diagnosis. Experience in Havana City

Introducción. Se hace un estudio de la incidencia y repercusión fenotípica del mosaicismo y seudomosaicismo cromosómico en diagnóstico prenatal en 18 años de labor en el laboratorio de Ciudad de La Habana.Métodos. Se incluyeron 10.676 amniocentesis cultivadas principalmente en frascos. El seguimiento de los casos se hace a través de especialistas y enfermeras en genética.Resultados y conclusiones. Se halló un 0,33 por ciento de mosaicismo en el muestreo, 4,50 por ciento de seudomosaicismo tipo I y 0,40 por ciento seudomosaicismo tipo II. Se detectaron 36 casos de mosaicos cromosómicos. El 70 por ciento del mosaicismo correspondió a aberraciones numéricas con paridad de aparición para los autosomas y los cromosomas sexuales; los mosaicos de aberraciones estructurales se hallaron en un 13,8 por ciento y los de marcadores cromosómicos supernumerarios en un 16,2 por ciento. El 42,2 por ciento de los fetos abortados o recién nacidos vivos con mosaicos cromosómicos fueron fenotípicamente normales a grosso modo. Se alcanzó un 63 por ciento de seguimiento citogenético en los casos de mosaicos cromosómicos. Las aberraciones cromosómicas mayormente involucradas en mosaicismo fueron la trisomía 21, la monosomía de la X y el cromosoma marcador supernumerario. Se hallaron 459 aberraciones cromosómicas asociadas al seudomosaicismo tipo I (327 aberraciones estructurales y 132 aberraciones numéricas). Fueron encontradas 48 aberraciones cromosómicas en el seudomosacismo tipo II, de las cuales 25 eran estructurales, 21 numéricas y 2 casos 46,XX/46,XY. Los cromosomas más frecuentemente hallados en seudomosaico fueron el 2, el 13, el 17, el 18, el 20 y el 21. La mayoría de los casos de seudomosaico el recién nacido fue normal. (AU)

Somatic mosaicism in FSHD often goes undetected.

Autosomal dominant facioscapulohumeral muscular dystrophy (FSHD1A) is associated with contractions of the polymorphic D4Z4 repeat array on chromosome 4qter. The disease has a high frequency of new mutations of mitotic origin. Pulsed-field gel electrophoresis-based studies show that mitotic mutations leading to somatic mosaicism occur equally frequently in patients and parents. Nevertheless, somatic mosaicism in FSHD is mainly reported in asymptomatic parents by applying standard Southern analysis after linear gel electrophoresis. Explaining this apparent discrepancy, we here demonstrate that somatic mosaicism in FSHD patients goes largely undetected using the standard diagnostic technique, indicating that linear electrophoresis is unsuitable to identify mosaic patients. As a consequence, the phenotype of mosaic patient's offspring will be underestimated, whereas the recurrence risk in the symptomatic mosaic individuals will be overestimated. Moreover, somatic mosaicism may partly explain the observation of anticipation in de novo kindreds. Therefore, clinicians should always consider pulsed-field gel electrophoresis analysis in de novo FSHD families, in particular when the patient's phenotype is much milder than expected based on D4Z4 length proper.

Prenatal diagnosis of premature centromere division-related mosaic variegated aneuploidy.

OBJECTIVES: To present the prenatal diagnosis of premature centromere division (PCD)-related mosaic variegated aneuploidy (MVA) and a review of the literature. CASE AND METHODS: A 33-year-old primigravida woman underwent amniocentesis at 22 weeks' gestation because of intrauterine growth restriction (IUGR), microcephaly, and oligohydramnios. Amniocentesis revealed PCD-related MVA. Repeat amniocentesis two weeks later consistently showed PCD-related MVA. The pregnancy was terminated. The proband postnatally manifested dysmorphic facial features of microcephaly, hypertelorism, low-set ears, a broad nasal bridge, a thin upper lip, and overriding toes. At autopsy, the internal organs were unremarkable. Cytogenetic analyses of the cord blood, liver, lungs, skin, and placenta displayed PCD-related MVA in all tissues studied. The PCD frequencies for the cells in the amniotic fluid (first culture), amniotic fluid (second culture), cord blood, liver, lungs, skin, and placenta were 53.3%, 56.5%, 47.4%, 38.7%, 33.9%, 33.3%, and 40.8% respectively. CONCLUSION: The present case provides evidence that, in cases of pregnancy with PCD-related MVA, the cytogenetic result of the amniocytes correlates well with those of the fetal cells and chorionic villi cells. We suggest that prenatal sonographic detection of a complex of IUGR, microcephaly and oligohydramnios with or without central nervous system abnormalities should include a differential diagnosis of PCD-related MVA.

Clinical, cytogenetic, and molecular findings of prenatally diagnosed mosaic trisomy 4.

OBJECTIVES: To present the clinical, cytogenetic, and molecular findings of prenatally diagnosed mosaic trisomy 4. CASE: An amniocentesis was performed at 21 weeks' gestation because of maternal anxiety. Cytogenetic analysis revealed mosaicism for trisomy 4, 47,XX,+4[4]/46,XX[16]. Level II ultrasound demonstrated tetralogy of Fallot. Repeated amniocentesis at 23 weeks' gestation revealed 47,XX,+4[4]/46,XX[19]. The pregnancy was terminated. Phenotypic findings included tetralogy of Fallot, hypertelorism, micrognathia, abnormal ears, duplicated phalanges of the left thumb, clinodactyly, and overlapping of the toes. The karyotype of the cord blood was 46,XX. Cytogenetic analyses of the multiple tissue samplings showed a karyotype of 47,XX,+4 in 40/40 cells of the amniotic membrane (amnion), and 47,XX,+4/46,XX with various levels of trisomy 4 in the cells of the liver, lungs, placenta, skin, and umbilical cord. The levels of trisomy 4 were 11/40 in the liver, 8/40 in the lungs, 31/40 in the placenta, 9/40 in the skin, and 8/40 in the umbilical cord. METHOD: The parental origin and meiotic origin of trisomy 4 were determined by examining the amniotic membrane using quantitative fluorescent polymerase chain reaction assays with polymorphic markers specific for chromosome 4. The result was consistent with a paternal meiosis I nondisjunction error. The cord blood showed a biparental inheritance. An extra paternal heterozygous allele with partial dosage increase was noted in other fetal and extraembryonic tissues studied. CONCLUSION: A diagnosis of trisomy 4 mosaicism in amniocytes indicates an increased risk for fetal abnormalities. Associated abnormal findings include congenital heart defects and anomalies of the digits and thumb. A confirmatory placental sampling may be helpful, whereas a fetal blood sampling is of a very limited value. A postnatal amnion sampling may provide additional clues to the fetal involvement of trisomy 4.

Prenatal diagnosis of mosaic distal 5p deletion and review of the literature.

OBJECTIVES: To present the prenatal diagnosis of mosaic distal 5p deletion and a review of the literature. CLINICAL SUBJECT AND METHODS: A 37-year-old woman, gravida 2, para 1, underwent genetic amniocentesis at 17 weeks' gestation because of advanced maternal age. Cytogenetic analysis of the cultured amniocytes revealed mosaicism for a distal 5p deletion, mos 46,XX,del(5)(p15.1)/46,XX (23 colonies/23 colonies). Repeat amniocentesis showed a consistent karyotype of mos 46,XX,del(5)(p15.1)/46,XX (12 colonies/15 colonies). The parental karyotypes were normal. Prenatal ultrasound demonstrated microcephaly and cerebellar hypoplasia. The pregnancy was terminated at 21 weeks' gestation. Postnatally, the fetus displayed microcephaly, a triangular face, hypertelorism, epicanthic folds, down-slanting palpebral fissures, low-set ears, and micrognathia. A karyotype of mos 46,XX,del(5)(p15.1)/46,XX was found in the cord blood, liver, lungs, and skin, whereas the placenta had a different karyotype of mos 46,XX,dup(5)(qter-->p15.3::p15.3-->p10)/46,XX, and the karyotype of the amnion was mos 46,XX,del(5)(p15.1)/46,XX,dup(5)(qter-->p15.3::p15.3-->p10)/46,XX,trp(5)(qter-->p15.3::p15.3-->p10::p10-->p15.3)/46,XX. The deletion, duplication, and triplication of the terminal region of the short arm of chromosome 5 were confirmed by the studies of fluorescence in situ hybridization. CONCLUSION: The cri-du-chat syndrome can be identified prenatally because of advanced maternal age, familial cri-du-chat syndrome, parental balanced translocations involving chromosome 5, sonographically detected fetal structural abnormalities, and/or an abnormal maternal serum test. Fetuses with the mosaic distal 5p deletion may be associated with the sonographic findings of microcephaly and cerebellar hypoplasia, and fetoplacental and fetoamnionic chromosomal discrepancies.

Structural chromosomal mosaicism and prenatal diagnosis.

True structural chromosomal mosaicism are rare events in prenatal cytogenetics practice and may lead to diagnostic and prognostic problems. Here is described the case of a fetus carrying an abnormal chromosome 15 made of a whole chromosome 2p translocated on its short arm in 10% of the cells, in association with a normal cell line. The fetal karyotype was 46,XX,add(15)(p10).ish t(2;15)(p10;q10)(WCP2+)[3]/46,XX[27]. Pregnancy was terminated and fetus examination revealed a growth retardation associated with a dysmorphism including dolichocephaly, hypertelorism, high forehead, low-set ears with prominent anthelix and a small nose, which were characteristic of partial trisomy 2p. Possible aetiologies for prenatal mosaicism involving a chromosomal structural abnormality are discussed.

Prenatal diagnosis of mos46,X,del(Y)(q11.2)/45,X by cytogenetic and molecular studies with multiplex STR analysis.

OBJECTIVES: To present the prenatal diagnosis of a fetus of mos46,X,del(Y)(q11.2)/45,X by cytogenetic and molecular analysis. CASE AND METHODS: A 35-year-old pregnant woman came to our hospital for amniocentesis, and fetal chromosomal aberrations with mos46,X, + mar/45,X were found. Fluorescence in situ hybridization revealed the existence of a Y centromere on the marker chromosome. Analysis with six pairs of short tandem repeat markers showed that the genomic DNA extracted from the uncultured amniotic fluid cells contained a deletion of Yq11.1-Yq11.2. Spermatogenesis loci of the Y chromosome were studied using four sets of multiplex PCR. The proximal two markers DYS271 and KALY were present and the other 16 distal markers were deleted. No deletion was noted in the Y chromosome of the father. RESULTS: Cytogenetic and molecular analyses revealed deletions of AZFb, d, and c regions on Yq11.2-Yqter in the fetal Y chromosome. Postmortem examination of the fetus showed a grossly normal male fetus with normal external genitalia and testes. CONCLUSION: The present report demonstrates that molecular analysis using polymorphic microsatellite markers and multiplex PCR is a useful complement to cytogenetic methods for the identification and the characterization of Y-chromosomal deletions.

Prenatal diagnosis of the distal 11q deletion and review of the literature.

OBJECTIVES: To present the prenatal diagnosis of de novo distal 11q deletions and a review of the literature. CLINICAL SUBJECTS AND METHODS: A 31-year-old primigravid woman underwent amniocentesis at 20 weeks' gestation because of a maternal serum alpha-fetoprotein (MSAFP) level of 2.63 multiples of the median. Amniocentesis demonstrated a karyotype of 46,XY,del(11)(q24.2). The parental karyotypes were normal. Level II ultrasound revealed short femurs and humeri, and overlapping of the toes. Postnatally, the proband manifested additional findings of the characteristic facial dysmorphism and camptodactyly. A 38-year-old gravida 2, para 1, woman underwent amniocentesis at 18 weeks' gestation because of advanced maternal age. Amniocentesis revealed a karyotype of 46,XX,del(11)(q24.1). The parental karyotypes were normal. Level II ultrasound did not show fetal structural abnormalities. Postnatally, the proband manifested characteristic facial dysmorphism and camptodactyly. RESULTS: Of these two cases, genetic marker analysis determined the paternally derived distal deletions of chromosome 11q and the deletion breakpoints. A comparison of the present cases with the reported cases of prenatally diagnosed distal 11q deletion is made. CONCLUSION: The distal 11q deletion can be identified prenatally because of parental balanced translocations involving chromosome 11, previous-term infants with an unbalanced rearrangement, advanced parental age, sonographically detected fetal abnormalities and abnormal maternal serum screening. Fetuses with de novo distal 11q deletions may be associated with elevated MSAFP and abnormal sonographic findings of the digits and limbs in the second trimester.

Trisomy 13 mosaicism: study of serial cytogenetic changes in a case from early pregnancy to infancy.

We report a patient whose chorionic villus sampling showed a nonmosaic trisomy 13 [46,XX,der(13;13)(q10;q10)]. Subsequent amniocentesis and cordocentesis showed varying percentages of abnormal cells (77 and 78% in two amniocentesis; 14% in cordocentesis) and mosaic trisomy 13 was impressed. Prenatal fetal ultrasound scanning revealed only mild structural abnormalities (echogenic cardiac foci, transient lemon head, transient skin oedema). The mother chose to continue the pregnancy. Karyotyping of the cord blood, peripheral blood, umbilical cord, urine, and chorion were performed postpartum. The process of correction appeared to exist in the placenta (indirect evidence from coexistence of trisomy 13 [46,XX,der(13;13)(q10,q10)], euploidy [46,XX], aneuploidy [46,XX,-13, +mar], and monosomy 13 [45,XX,-13] in the chorion at birth). The baby had survived beyond eight months of age at the time of submission. Few structural abnormalities except low-set ears, absence of the 12th rib, and cardiomegaly with ventricular septal defect, were noted postnatally. The growth reached 95th percentile at the age of one month. Development milestones were not delayed at serial evaluations. Her ventricular septal defect was corrected surgically at the age of six months. Karyotypes of her skin fibroblasts, blood lymphocytes, and cardiac tissue were all normal [46,XX] at the time of surgery. Difficulties of the genetic counseling are also discussed.

Molecular and cytogenetic characterization of extra-structurally abnormal chromosomes (ESACs) found prenatally: outcome and follow-up.

A 40-year-old woman underwent amniocentesis at 15.3 weeks of gestation. Chromosome analysis performed using QFQ, DA-DAPI and CBG banding revealed two de novo extra-chromosomal markers (ESACs) in 11 of the 16 colonies analysed. Fluorescence in situ hybridization (FISH) showed that both chromosomes came from the Yq11.22.1 region of the Y chromosome. PCR analysis of genes and STS localized on the Y chromosome excluded the Yp presence specifically of the SRY gene, and most of the euchromatic region of Yq. After extensive genetic counselling and considering both laboratory and second-level ultrasound data, the couple decided to continue the pregnancy. At 37.4 weeks of gestational age, a girl weighing 2750 g was born with an Apgar score of 9/10. A blood sample taken from the umbilical cord showed three cellular lines: mos47,XX, +mar1 ish.der (Y)(wcpY+) [21%]/48,XX, +mar1 ish.der (Y)(wcpY+), +mar2 ish.der (Y)(wcpY+) [41%]/46,XX [38%]. One year after birth, the baby was developing normally and had normal psychomotorial activity.

Possible human chimera detected prenatally after in vitro fertilization: a case report.

BACKGROUND: Chimerism is the coexistence of more than one cell line in an individual, due to the fusion of originally separate zygotes. It has been very rarely described in humans. METHODS: A 36-year-old woman who was referred for in vitro fertilization (IVF) for unexplained infertility had three embryos transferred. RESULTS: Four weeks and five days after the transfer, ultrasound examination detected a single fetus in the uterus. Ultrasound examination at 17 weeks for metrorrhagia showed severe intrauterine growth retardation. Amniocentesis revealed a mixture of 46,XY and 46,XX clones. Histopathologic examination showed a dysmorphic fetus with female phenotype and severe growth retardation. CONCLUSIONS: Although demonstration by fingerprinting has not been possible, fusion of two of the three transferred embryos (one male and one female) seems to be the most probable mechanism that could explain both cytogenetic and histopathologic observations. No chimera has yet been described after IVF. It would be interesting to collect any such observations from other IVF centers.