Clinical, imaging, and molecular findings in a sample of Mexican families with pantothenate kinase-associated neurodegeneration.

Pantothenate kinase-associated neurodegeneration (PKAN) is an autosomal recessive disorder characterized by iron accumulation in the brain, because of mutations in the PANK2 gene. Phenotypic and genotypic characteristics of 11 patients from five Mexican families with PKAN disease are reported. Sequencing of PANK2 confirmed the diagnosis. The 11 patients had dysarthria associated with dystonia and Parkinsonism in six. Brain magnetic resonance imaging (MRI) showed the 'eye-of-the-tiger' sign in all patients. Three different mutations were identified, a novel one (p.A469P) and two (p.G219V and p.N404I) very rare. Homozygous sibs for the p.G219V mutation had a severe disease progression with early death. Dystonia predominated in the p.A469P/p.N404I compound heterozygous patients. Homozygous for p.N404I showed Parkinsonism, tics and personality and speech disorders. Early and late disease onset and variable expression was present in carriers of the different identified mutations. The 'eye-of-the-tiger' is an excellent neuroimaging hallmark to predict PANK2 mutations. We detected a 'cluster' of patients harboring the p.N404I mutation, strongly suggesting a founder effect for this mutation. This is the first familial clinical-genetic PKAN disease study accomplished in Mexico.

Failure of adjusted doses of subcutaneous heparin to prevent thromboembolic phenomena in pregnant patients with mechanical cardiac valve prostheses.

OBJECTIVES: This report describes our experience with the use of an anticoagulant regimen of adjusted doses of subcutaneous heparin during pregnancy in women with cardiac valve prostheses. BACKGROUND: Gravid patients with prosthetic heart valves require long-term anticoagulant therapy. To avoid the increased incidence of fetal morbidity and mortality associated with the use of coumarin agents in such patients during pregnancy, anticoagulation with subcutaneous heparin has been suggested. Controversy exists concerning the appropriate treatment of these patients. METHODS: Forty pregnancies in 37 women with prosthetic heart valves were prospectively followed up. Subcutaneous heparin was administered from the 6th until the end of the 12th week and in the last 2 weeks of gestation. Heparin was given every 8 h in the first 36 cases and every 6 h in the last 4 cases, and the dose adjusted to maintain the activated partial thromboplastin time at 1.5 to 2.5 times the control level. Acenocoumarol was used at other times. RESULTS: The incidence rate of spontaneous abortions was 37.5%; there was one neonatal death (2.5%) due to cerebral hemorrhage. No signs of coumarin-induced embryopathy were found in any of the 16 live-born infants studied by the geneticist. One mother died of gastrointestinal bleeding while receiving oral anticoagulant agents. There were two cases of fatal massive thrombosis of a mitral tilting-disk prosthesis during heparin therapy. The study was interrupted after the last of these two cases. CONCLUSIONS: The regimen of adjusted doses of subcutaneous heparin used in this study is not effective to prevent thrombosis of mechanical valve prostheses during pregnancy. The use of heparin from the 6th to the 12th week of gestation does not decrease the high incidence of fetal wastage associated with anticoagulant therapy. Coumarin agents provide adequate protection against thromboembolism during pregnancy in patients with mechanical valve prostheses.

Endocrine and biochemical studies in a 46,XY phenotypically male infant with 17-ketosteroid reductase deficiency.

A 46,XY phenotypically male patient with 17-ketosteroid reductase deficiency is described. The patient was a 6-month-old infant who presented with micropenis and bilateral cryptorchidism. Baseline plasma levels of testosterone (T), delta 4-androstenedione (delta 4A), and 5 alpha-dihydrotestosterone (5 alpha-DHT) were within the normal range [patient: 0.17 (T), 0.12 (delta 4A), and 0.032 (5 alpha-DHT) ng/ml; normal infants: 0.03-0.55 (T), 0.14-0.45 (delta 4A), and 0.01-0.23 (5 alpha-DHT) ng/ml]. hCG administration induced a significant rise in plasma delta 4A levels (up to 8.39 ng/ml) and a slight increase in T and 5 alpha-DHT levels. The delta 4A/T ratios before and during the hCG challenge were 0.86 and 55.61, respectively (controls: 0.83 and 0.13). Incubation of genital skin-derived fibroblasts from the patient with either [3H]T or [3H] delta 4A revealed normal formation of delta 4A from T and diminished conversion of delta 4A to T. The development of a male phenotype despite both a testicular and peripheral 17-ketosteroid reductase deficiency is difficult to explain. It is possible that the fetal testes were the source of sufficient amounts of T during the early periods of embryonic life, and that late onset of the enzyme deficiency prevented the development of completely normal male genitalia. The in vitro finding of normal T to delta 4A conversion by the mutant fibroblasts suggests that in this particular tissue 17 beta-reduction and dehydrogenation of androgens are mediated by two isoenzymes with distinct substrate and/or cofactor specificities.

Combined trisomy 9 and Ullrich-Turner syndrome in a girl with a 46,X,der(9)t(X;9)(q12;q32) karyotype.

Total trisomy 9 is a rare disorder with most patients dying before age 4 months. Herein, we report a 9-year-old girl with mental retardation, short stature, a peculiar face and other minor defects, who was diagnosed as having an unbalanced de novo X-autosome translocation with a 46,X,der(9)t(X;9)(q12;q32) karyotype resulting in almost a full trisomy 9(pter-->q32) and a partial monosomy X(q12-->pter). The clinical findings of our patient, almost exclusively resemble those of trisomy 9p and the Ullrich-Turner syndromes and has few manifestations of 9q trisomy. BrdU replication studies by Giemsa staining showed an earlier replication of 9p in the translocated chromosome, but a marked late-replication pattern for almost the complete 9q arm involved in the translocation. FISH studies confirmed the presence of three 9 centromeres, excluded the presence of the X centromere signal in the rearranged chromosome, and showed that both Xq telomeric sequences were present. BrdU replication studies by FISH showed an usual pattern of striking late-replication around the XIC of the derivative chromosome, but early replication of the chromosome 9p segment and distal Xq.

Duplication 11q and deletion 5p syndromes due to a reciprocal translocation segregating in four generations.

We report on 2 relatives with duplication 11q and deletion 5p, resulting from an adjacent-1 segregation of a balanced reciprocal translocation 5p15;11q23, segregating in 4 generations of this family. Twelve out of 16 at-risk relatives of inheriting the translocation were shown to be carriers, giving a significant (p less than .05) 3:1 ratio of carriers/noncarriers. The breakpoint on chromosome 11 at q23 is a folate sensitive fragile site into where the proto-oncogene c-ets has been mapped.

Miller-Dieker syndrome and trisomy 5p in a child carrying a derivative chromosome with a microdeletion in 17p13.3 telomeric to the LIS1 and the D17S379 loci.

Trisomy 5p and Miller-Dieker syndromes frequently are the result of unbalanced segregations of reciprocal translocations of chromosomes 5 and 17 with other autosomes. The critical regions for the expression of the mentioned syndromes have been mapped to 5p13-->pter, and 17p13.3-->pter. In this report, we describe an 8-year-old girl with mental retardation, postnatal growth deficiency, generalized muscular hypotonia, seizures, microcephaly, cortical atrophy, partial agenesis of corpus callosum, cerebral ventriculomegaly, facial anomalies, patent ductus arteriosus, pectus excavatum, long fingers, and bilateral talipes equinovarus caused by the presence of a 46,XX,der(17)t(5;17)(p13.1;p13.3)mat chromosome complement. Cytogenetic studies of the family confirmed a balanced reciprocal translocation (5;17)(p13.1;p13.3) in her mother, maternal grandfather, maternal aunt, and a female first cousin. Fluorescence in situ hybridization studies on the mother and the proposita using three probes, which map to distal 17p, confirmed the reciprocal translocation in the mother and a terminal deletion in the patient, which resulted in the retention of LIS1 and D17S379 loci and deletion of the 17p telomere. These findings and the phenotype of the proposita, strongly suggest that genes telomeric to LIS1 and locus D17S379 are involved in many clinical findings, including the minor facial anomalies of the Miller-Dieker syndrome.

Gerodermia osteodysplastica hereditaria: report of three affected brothers and literature review.

Gerodermia osteodysplastica hereditaria was diagnosed in three Mexican brothers 6, 7, and 8 years old, respectively, who had the distinct facial appearance with sagging cheeks, premature wrinkling of the skin of face, abdomen, and dorsum of hands and feet; malocclusion, span greater than height; hyperextensibility; winging of the scapulae; stooped posture with kyphoscoliosis; protuberant abdomen; and pes planus. Radiologically they had generalized osteoplorosis, platyspondily due to multiple compression fractures, pseudoepiphyses of second metacarpals, and dislocated hips. Three other families with a total of 14 affected individuals have been reported. Inter- and intrafamilial variability can be recognized, particularly regarding the tendency to fractures, upper:lower segment ratio abnormalities, and results of skin biopsies, which have shown fragmentation of the elastic fibers in some cases (including the present family) and not in others. Although inheritance was considered to be X-linked recessive in the first reported family, an analysis of that pedigree together with those of the other reported families, including the present one, suggests that gerodermia osteodrysplastica is inherited in an autosomal recessive manner.

Fetal mortality in sibships with one or more affected members with oral clefts.

We investigated the fetal mortality in 903 sibships with at least one member having cleft lip with or without cleft palate [CL(P)] and 213 with at least one individual affected with cleft palate (CP) derived from three different data sources in México. The frequency of fetal wastage (abortion and/or stillbirth) was not increased in sibships where the propositi had cleft lip and palate (CLP) as compared with cleft lip (CL) nor in those where index cases had a bilateral lesion as compared to a unilateral one, nor when the index cases with CL(P) were female rather than males, nor when the index case was a female with bilateral lesion as compared to males with a unilateral one. Similarly fetal mortality was not increased in sibships in which the propositus had CP compared to those in which the index case was a female. These findings are contrary to some reports that claim to support a two-threshold model according to which individuals reaching the first one would be born with an oral cleft, and those reaching the second would be aborted. Our results, together with others, suggest the possibility that liability to oral clefts is independent of liability to fetal wastage.

Mixed gonadal dysgenesis: clinical, cytogenetic, endocrinological, and histopathological findings in 16 patients.

We describe clinical, cytogenetic, endocrine, and histopathological findings in 16 patients with mixed gonadal dysgenesis (MGD). All patients except 1 presented genital ambiguity and 10 of them had Ullrich-Turner manifestations. The 45,X/46,XY karyotype was the most frequent with a predominance of 45,X cells in both peripheral lymphocytes and gonads. In all cases Müllerian and Wolffian remnants and/or derivatives were found and in some patients both Wolffian- and Müllerian-derived structures were identified on the streak or testicular side. Postpubertal patients exhibited variable degrees of virilization and all of them had hypergonadotropism coexisting with low to normal baseline serum levels of testosterone; their testicular response to human chorionic gonadotropin (HCG) in terms of testosterone secretion was also variable, ranging from minimal to almost a normal response. All prepubertal patients but 1 had normal baseline levels of pituitary gonadotropins and testosterone and their gonadal response to the HCG challenge was highly variable. With the exception of 1 case, who had a 45,X/46,XY(p-) karyotype, no correlation between the cytogenetic data and degree of external genital ambiguity and the hormonal findings was observed. Additional information on the specific structural abnormalities involving the testis-determining gene of the Y chromosome in patients with MGD is needed in order to further understand the mechanisms responsible for the wide variability characteristic of this disorder.

Congenital malformations in twins: an international study.

Data provided by nine registries based in European and Latin America countries were analyzed to assess whether there is an excess of malformations in twins compared to singletons. Specific congenital malformations were coded according to the ninth revision of the International Classification of Diseases (ICD). Malformation rates and rate ratios (RR) for twins compared to singletons were calculated for each registry, and the homogeneity of the RRs was tested using the test of Breslow and Day. If departure from homogeneity in the different registries was not significant, registry-adjusted RRs with 95% confidence intervals were calculated. Overall, among 260,865 twins, 5,572 malformations were reported. A total of 101 different types of malformations or groups of defects was identified, and a homogeneous estimate of the RRs among registries was found for 91.1% of the malformations. Thirty-nine of the 92 malformations with homogeneous estimates of RRs were more common in twins than in singletons. For the remaining nine malformations, heterogeneous estimates of RRs were obtained. This study confirms the majority of already known associations and further identifies previously unreported malformations associated with twins. In conclusion, there is an excess of malformations in twins compared with singletons, and all anatomical sites are involved. The number of specific malformations associated with twins is higher than that previously reported in smaller studies.

Limb defects associated with major congenital anomalies: clinical and epidemiological study from the International Clearinghouse for Birth Defects Monitoring Systems.

Although limb defects associated with other congenital anomalies are rarely studied, they may provide insights into limb development that may be useful for etiologic studies and public health monitoring. We pooled data from 11 birth defect registries that are part of the International Clearinghouse for Birth Defects Monitoring Systems. We identified 666 infants, born from 1983 through 1993, who had a non-syndromal limb defect plus at least one other major malformation (rate 12.9/100,000 population). We used observed/expected ratios and log-linear models to detect association patterns. We found that specific limb defects occurred with relatively distinct sets of malformations. Preaxial limb defects occurred more frequently with microtia, esophageal atresia, anorectal atresia, heart defects, unilateral kidney dysgenesis, and some axial skeleton defects; postaxial defects with hypospadias; transverse defects with craniofacial defects, micrognathia, ring constrictions, and muscular defects; intercalary defects with omphalocele; split hand/foot with encephalocele; and amelia with anorectal atresia, omphalocele, severe genitalia defects, unilateral kidney dysgenesis, gastroschisis, and ring constriction. Log-linear modeling identified higher order associations among some of these same malformations.

The spectrum of congenital anomalies of the VATER association: an international study.

The spectrum of the VATER association has been debated ever since its description more than two decades ago. To assess the spectrum of congenital anomalies associated with VATER while minimizing the distortions due to small samples and referral patterns typical of clinical series, we studied infants with VATER association reported to the combined registry of infants with multiple congenital anomalies from 17 birth defects registries worldwide that are part of the International Clearinghouse for Birth Defects Monitoring Systems (ICB-DMS). Among approximately 10 million infants born from 1983 through 1991, the ICB-DMS registered 2,295 infants with 3 or more of 25 unrelated major congenital anomalies of unknown cause. Of these infants, 286 had the VATER association, defined as at least three of the five VATER anomalies (vertebral defects, anal atresia, esophageal atresia, renal defects, and radial-ray limb deficiency), when we expected 219 (P<0.001). Of these 286 infants, 51 had at least four VATER anomalies, and 8 had all five anomalies. We found that preaxial but not other limb anomalies were significantly associated with any combination of the four nonlimb VATER anomalies (P<0.001). Of the 286 infants with VATER association, 214 (74.8%) had additional defects. Genital defects, cardiovascular anomalies, and small intestinal atresias were positively associated with VATER association (P<0.001). Infants with VATER association that included both renal anomalies and anorectal atresia were significantly more likely to have genital defects. Finally, a subset of infants with VATER association also had defects described in other associations, including diaphragmatic defects, oral clefts, bladder exstrophy, omphalocele, and neural tube defects. These results offer evidence for the specificity of the VATER association, suggest the existence of distinct subsets within the association, and raise the question of a common pathway for patterns of VATER and other types of defects in at least a subset of infants with multiple congenital anomalies.

Monitoring dominant germ cell mutations using skeletal dysplasias registered in malformation registries: an international feasibility study.

Using data from seven malformation monitoring systems around the world, the feasibility of monitoring fresh dominant mutations using skeletal dysplasias was explored. Based on a total of over 9.5 million births, 1500 infants with skeletal dysplasias were identified (16 per 100,000). In spite of efforts to get exact diagnoses, an average of 21% were unspecified. Comparisons of rates of specific diagnoses in different programmes suggested that classification differed. By analysing maternal age distribution, estimates were made of the proportion of fresh mutations in different subgroups: conditions regarded as dominant (achondroplasia, thanatophoric dysplasia, spondyloepiphyseal dysplasia) were estimated to consist of 58% fresh mutations--some of the remaining cases were inherited, others were probably misclassified. Among conditions regarded as recessive, only 5% were estimated to be truly dominant mutations. In the total group of skeletal dysplasias, 21% were estimated to be fresh dominant mutations and if osteogenesis imperfecta were excluded, the figure was 31%. By power analyses it was shown that equal monitoring power may be obtained by a programme covering about 45,000 births per year with intensive diagnosis of each individual case of skeletal dysplasia and a programme some three times greater where no specific diagnoses are obtained. An increasing trend in the occurrence of skeletal dysplasias was seen but probably explained by changing ascertainment. An impact of antenatal diagnosis resulting in a decrease in occurrence was also apparent in some programmes.

Molecular differentiation of two different translocations producing two apparent Ph chromosomes in a patient with CML.

A case of chronic myelogenous leukemia (CML) is described whose leukemic cells appeared to contain two Philadelphia (Ph) chromosomes originating from different translocations involving the two chromosomes 22. The karyotype of the affected cells, established on two different occasions, was: 46,XY,t(9;22)(q34;q11),t(15;22)(p11;q11) with no normal chromosomes 22 and only one 9q+ in each of 115 marrow cells examined. The same findings were present in 50 peripheral blood cells cultured without phytohemagglutinin (PHA) stimulation. When stimulated with PHA, a normal male karyotype was present in the 11 cells examined. There were no additional chromosomal abnormalities and no indication of a blastic crisis after nearly 1 year following the original study. Analysis of the breakpoint cluster region (bcr) on chromosome 22 in the DNA of the affected cells (marrow) revealed evidence for one rearranged chromosome 22 and one normal chromosome 22, indicating that the t(15;22) was not due to the usual Ph translocation seen in CML. The results point to the crucial usefulness of molecular analysis in confirming cytogenetic results related to Ph translocations in CML.

An international collaborative study of the epidemiology of esophageal atresia or stenosis.

Epidemiologic data were analyzed for a total of 2,693 infants with esophageal atresia registered in nine congenital malformation registries around the world. The average recorded prevalence at birth was 2.6 per 10,000 births, with a significant variability among programs--and sometimes within a program--and a maximum prevalence of above 3 per 10,000 births. Clusters of infants with esophageal atresia were observed but may be random. An increasing rate was seen during the period 1965 to 1975 (Norway, South America, Sweden). The type of esophageal atresia was specified in only 439 cases, but no major differences were seen in the epidemiologic characteristics of infants with the most common type (distal fistula) and infants with other types. There was an excess of low birth weight and preterm birth, and infants with esophageal atresia had a birth weight 500 to 1,000 g less than normal infants in each gestational week. There was an excess of twins, apparently mainly or exclusively due to monozygotic twinning, but in only two pairs did both twins have esophageal atresia. There was no effect seen of maternal age, but low parity, irrespective of maternal age, was associated with an increased risk for esophageal atresia. Infant survival varied among programs and depended heavily on associated malformations. Among 1,107 sibs born before the proband and 385 born after the proband, only 25 (1.7%) had a serious malformation; three had esophageal atresia. In 57.3% of the infants with esophageal atresia, no other malformations were present, in 36.4% other major malformations were recorded, and in 6.3% there were chromosomal anomalies. The malformations present associated with esophageal atresia were analyzed: a large proportion entered the constellation sometimes called "caudal mesoderm spectrum of malformations": VATER, Potter, and caudal regression sequences.

Human lymphocyte proliferation kinetics in Hanks' BSS supplemented with autologous plasma and in synthetic medium.

Human lymphocyte proliferation kinetics was studied in different culture conditions including synthetic medium, Hanks' BSS and Hanks' supplemented with autologous plasma at several culture times. Even though mitotic indices (MI) were low, lymphocytes were able to divide for a few cycles in BSS alone, with a cycling time of around 24 h. Similar cell proliferation patterns with similar MIs, replication indices and cell cycle times of approximately 12 h were obtained with RPMI 1640 and with autologous plasma-supplemented BSS, although lymphocytes exhibited a more uniform MI distribution curve in synthetic medium. The findings mentioned above suggest that Hanks' with autologous plasma may represent a suitable and inexpensive culture condition to avoid undesirable side effects related to synthetic media and heterologous sera, for diagnostics as well as research cytogenetics.

Sister-chromatid exchanges and cell kinetics in human and rabbit lymphocytes exposed in vivo and in vitro to 2-bromo-alpha-ergocryptine.

The possible mutagenic and DNA-synthesis inhibitory effects of 2-bromo-alpha-ergocryptine, a new semi-synthetic ergot alkaloid, was studied in human and rabbit lymphocytes exposed to it in vivo and in vitro. The analysis of SCE was mainly used to evaluate potential mutagenicity, and the mitotic and DNA-synthesis inhibition was explored by examining the proportions of first-, second- and third-division metaphases in the corresponding lymphocyte cultures. The results obtained show that 2-bromo-alpha-ergocryptine does not induce SCE in the cell systems tested, or structural chromosome aberrations in human lymphocytes in vivo. On the other hand, a marked mitotic inhibitory effect and associated cell kinetic changes could be clearly attributed to the drug, probably related to its cytotoxicity.

Oral contraceptives in the etiology of isolated hypospadias.

With the objective of identifying whether hypospadias in infants is associated with maternal use of oral contraceptives before pregnancy or in early pregnancy, 846 case-control pairs were collected from eight different malformation monitoring programs around the world and mothers were interviewed using structured questionnaires administered after the birth of the infants. There was no difference in the preconceptional use of oral contraceptives between cases and controls, neither with respect to the number of years of oral contraceptive usage nor the time between stopping oral contraceptives and the present pregnancy. To this material was added data on oral contraceptive usage in early pregnancy from two other sources: an ongoing case-control study in Spain (725 infants with hypospadias) and a population-based study in Sweden (631 infants with hypospadias). There was no statistically significant difference in oral contraceptive exposure in early pregnancy between cases and controls. There is no demonstrable association between oral contraceptive use and infant hypospadias.

Hypopituitarism in two brothers born by breech delivery.

OBJECTIVE: To describe two brothers with hypopituitarism who had been born by breech delivery and to discuss whether this condition corresponds to a familial form or to a pituitary stalk section as a result of the breech delivery. METHODS: We present the clinical, biochemical, and magnetic resonance imaging (MRI) characteristics of two Mexican brothers, 19 and 21 years old, with hypopituitarism and a history of breech delivery. RESULTS: Physical examination of both patients showed short stature with normal body proportions, an obviously younger appearance than that expected for their chronologic age, high-pitched voice, irregularly positioned teeth, no axillary or pubic hair, and prepubertal genitalia. Biochemical testing showed low thyroxine and free thyroxine values with inadequate or normal thyrotropin, low basal testosterone, and mildly increased serum prolactin levels. Stimulation tests showed a normal and a delayed thyrotropin response to thyrotropin-releasing hormone, subnormal serum cortisol, considerably blunted growth hormone (GH) response to insulin-induced hypoglycemia, and absence of GH response to GH-releasing hormone in both cases. MRI showed an ectopic neuropituitary gland. In case 1, a caudal portion of a very thin pituitary stalk was observed, suggesting the preservation of a vascular component of the stalk. Because both parents of these brothers shared the major histocompatibility complex haplotype HLA-A*2301, B*3501, DRB1*0407, DQA1*03, DQB1*0201, consanguinity was suggested. CONCLUSION: The phenotype of these patients differs from that described in families with POU1F1 (Pit-1) and PROP1 mutations. These cases are most likely related to an autosomal recessive gene mutation that warrants further research. To our knowledge, this is the first report of hypopituitarism in two brothers born by breech delivery.

Endocrine evaluation in a patient with MURCS association and ovarian agenesis.

A new case of Mullerian duct aplasia, renal aplasia, and cervicothoracic somite dysplasia (MURCS association) in a 16-yr-old female patient is reported. In addition, agenesis of the right ovary plus hypoplasia of the right craniofacial bones were also present. Dynamic tests of anterior pituitary reserve (LH-RH, TRH and hypoglycemia) showed normal responsiveness of this gland in terms of LH, FSH, TSH, prolactin and growth hormone secretion, whilst a subnormal plasma cortisol response to hypoglycemia and exogenous ACTH (in the presence of unilateral adrenal agenesis) was found. Functional integrity of the hypothalamic-pituitary-ovarian axis was also documented. The presence of two additional and previously unreported congenital anomalies in this patient with MURCS association underlines the wide spectrum of the syndrome.