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INTRODUCTION A gene-environment interaction between expression genotypes of the monoamine oxidase A (MAOA) and adverse childhood experience increases the risk of antisocial behavior. However, the neural underpinnings of this interaction remain uninvestigated. A cortico-limbic circuit involving the prefrontal cortex (PFC) and the amygdala is central to the suppression of aggressive impulses and is modulated by serotonin (5-HT). MAOA genotypes may modulate the vulnerability of this circuit and increase the risk for emotion regulation deficits after specific life events. Acute tryptophan depletion (ATD) challenges 5-HT regulation and may identify vulnerable neuronal circuits, contributing to the gene-environment interaction. METHODS Functional magnetic resonance imaging measured the resting-state state activity in 64 healthy males in a double-blind, placebo-controlled study. Cortical maps of amygdala correlation identified the impact of ATD and its interaction with low- (MAOA-L) and high-expression variants (MAOA-H) of MAOA on cortico-limbic connectivity. RESULTS Across all Regions of Interest (ROIs) exhibiting an ATD effect on cortico-limbic connectivity, MAOA-L carriers were more susceptible to ATD than MAOA-H carriers. In particular, the MAOA-L group exhibited a larger reduction of amygdala connectivity with the right prefrontal cortex and a larger increase of amygdala connectivity with the insula and dorsal PCC. CONCLUSION MAOA-L carriers were more susceptable to a central 5-HT challenge in cortico-limbic networks. Such vulnerability of the cortical serotonergic system may contribute to the emergence of antisocial behavior after systemic challenges, observed as gene-environment interaction. Hum Brain Mapp 38:1622-1635, 2017. © 2016 Wiley Periodicals, Inc.

Introduction Heterozygous BICD2 gene mutations cause a form of autosomal dominant spinal muscular atrophy with lower extremity predominance (SMALED). Methods We analyzed the BICD2 gene in a selected group of 25 index patients with neurogenic muscle atrophy. Results We identified 2 new BICD2 missense mutations, c.2515G>A, p.Gly839Arg, in a family with autosomal dominant inheritance, and c.2202G>T, p.Lys734Asn, as a de novo mutation in an isolated patient with similar phenotype. The patients had congenital foot contractures, muscle atrophy of the legs, and slowly progressive weakness of the shoulder girdle. There was no apparent sensory or brain dysfunction. One patient died of unrelated reasons at age 52 years. Autopsy revealed no upper motor neuron and only moderate lower motor neuron loss, but there was distal corticospinal tract degeneration and marked neurogenic muscular atrophy. Conclusion These findings give further insight into the clinical and pathoanatomical consequences of BICD2 mutations. Muscle Nerve 54: 496–500, 2016

Silver-Russell syndrome (SRS) is a growth retardation syndrome characterized by intrauterine and postnatal growth retardation, relative macrocephaly and protruding forehead, body asymmetry and feeding difficulties. Nearly 50% of cases show a hypomethylation in 11p15.5, in 10% maternal uniparental disomy of chromosome 7 is present. A significant number of patients with SRS features also exhibit chromosomal aberrations. We analyzed 43 individuals referred for SRS genetic testing by molecular karyotyping. Pathogenic variants could be detected in five of them, including a NSD1 duplication in 5q35 and a 14q32 microdeletion. NSD1 deletions are detectable in overgrowth disorders (Sotos syndrome and Beckwith-Wiedemann syndrome), whereas NSD1 duplications are associated with growth retardation. The 14q32 deletion is typically associated with Temple syndrome (TS14), but the identification of a patient in our cohort reflects the clinical overlap between TS14 and SRS. As determination of molecular subtypes is the basis for a directed counseling and therapy, the identification of pathogenic variants in >10% of the total cohort of patients referred for SRS testing and in >16% of characteristic individuals with the characteristic SRS phenotype confirms the need to apply molecular karyotyping in this cohort.

We present clinical features and genetic results of 1206 index patients and 124 affected relatives who were referred for genetic testing of Charcot-Marie-Tooth (CMT) neuropathy at the laboratory in Aachen between 2001 and 2012. Genetic detection rates were 56% in demyelinating CMT (71% of autosomal dominant (AD) CMT1/CMTX), and 17% in axonal CMT (24% of AD CMT2/CMTX). Three genetic defects (PMP22 duplication/deletion, GJB1/Cx32 or MPZ/P0 mutation) were responsible for 89.3% of demyelinating CMT index patients in whom a genetic diagnosis was achieved, and the diagnostic yield of the three main genetic defects in axonal CMT (GJB1/Cx32, MFN2, MPZ/P0 mutations) was 84.2%. De novo mutations were detected in 1.3% of PMP22 duplication, 25% of MPZ/P0, and none in GJB1/Cx32. Motor nerve conduction velocity was uniformly 40 m/s in MFN2, and more variable in GJB1/Cx32, MPZ/P0 mutations. Patients with CMT2A showed a broad clinical severity regardless of the type or position of the MFN2 mutation. Out of 75 patients, 8 patients (11%) with PMP22 deletions were categorized as CMT1 or CMT2. Diagnostic algorithms are still useful for cost-efficient mutation detection and for the interpretation of large-scale genetic data made available by next generation sequencing strategies.

Background: Myotonic dystrophy type 2 (DM2) is an autosomal dominant multisystem disorder caused by CCTG repeat expansions within intron 1 of the ZNF9 gene on chromosome 3q. Cardiac conduction disturbances, supraventricular arrhythmias, and cardiomyopathy are described in DM2 but Brugada-like features have not yet been reported. Brugada syndrome (BS) is a genetically heterogeneous cardiac conduction disorder which is characterized by a significant ST-segment elevation upon ECG evaluations and bears an increased risk for sudden cardiac death. Case reports: We report two unrelated patients with genetically confirmed DM2 who developed clinical relevant cardiac arrhythmias with syncopal events from 35 (patient 1) and 47 years (patient 2). Brugada-like ECG findings were present in both patients. Family history was negative for BS, but the mothers of both index patients were also affected by DM2 and had different ventricular rhythm disturbances. SCN5A gene sequencing revealed an unknown genetic variant c.4140 C > A, p.N1380K, in patient 1, while no mutation was detected in patient 2. Discussion: Our observations may suggest that Brugada-like cardiac arrhythmias can occur in DM2, as this seems also to be the case in DM1. The chance association of two independent inherited disorders has to be considered and cannot be excluded in one of our patients. However, on statistical grounds, this possibility cannot explain all observed cases of DM with Brugada-like cardiac disease.

Unlike atrophy of the corpus callosum (CC), callosal hypertrophy is a rare neuroimaging finding with only few reported patients. The "megalencephaly, mega CC, and complete lack of motor development" syndrome is morphologically characterized by generalized megalencephaly, a thickened CC, and extensive polymicrogyria causing a pachygyric appearance. We report on the fifth patient showing this rare syndrome, a 3-year-old girl displaying the typical neuroimaging features. Clinically she showed a severely impaired motor, mental, and speech development with marked muscular hypotonia but no dysmorphic facial signs. She also retained the ability to move by rolling sidewards so that complete lack of motor development may not be a consistent feature.

Infantile spinal muscular atrophy (SMA) caused by homozygous SMN1 gene deletions/mutations is characterized by neuronal loss and axonopathy of motor neurons. We report two unrelated patients with severe SMA type I who had only one SMN2 copy and developed ulcerations and necroses of the fingers and toes. Sural nerve biopsy was normal in patient 1, whose affected skin displayed necroses and thrombotic occlusions of small vessels. Corresponding to a mouse model and other patients with similar findings, we believe that severe survival motor neuron (SMN) deficiency may present as vasculopathy.

Impaired performance in verbal fluency tasks is an often replicated finding in schizophrenia. In functional neuroimaging studies, this dysfunction has been linked to signal changes in prefrontal and temporal areas. Since schizophrenia has a high heritability, it is of interest whether susceptibility genes for the disorder, such as NRG1, modulate verbal fluency performance and its neural correlates. Four hundred twenty‐nine healthy individuals performed a semantic and a lexical verbal fluency task. A subsample of 85 subjects performed an overt semantic verbal fluency task while brain activation was measured with functional magnetic resonance imaging (MRI). NRG1 (SNP8NRG221533; rs35753505) status was determined and correlated with verbal fluency performance and brain activation. For the behavioral measure, there was a linear effect of NRG1 status on semantic but not on lexical verbal fluency. Performance decreased with number of risk‐alleles. In the fMRI experiment, decreased activation in the left inferior frontal and the right middle temporal gyri as well as the anterior cingulate gyrus was correlated with the number of risk‐alleles in the semantic verbal fluency task. NRG1 genotype does influence language production on a semantic level in conjunction with the underlying neural systems. These findings are in line with results of studies in schizophrenia and may explain some of the cognitive and brain activation variation found in the disorder. More generally, NRG1 might be one of several genes that influence semantic language capacities. Hum Brain Mapp, 2009. © 2009 Wiley‐Liss, Inc.

Robertsonian translocations 13/14 are the most common chromosome rearrangements in humans. However, most studies aimed at determining risk figures are more than 20 years old. Their results are often contradictory regarding important topics in genetic counseling such as infertility and unfavorable pregnancy outcomes. Here, we present a study on a sample of 101 previously unreported pedigrees of der(13;14)(q10;q10). In order to minimize problems of partial ascertainment, we included families with a wide range of reasons of ascertainment such as birth of a child with congenital anomalies, prenatal diagnosis due to maternal age, fertility problems and recurrent pregnancy loss. No evidence of increased infertility rates of female and male carriers was found. The detected miscarriage frequency of female carriers was higher than previously reported (27.6 +/- 4.0% of all spontaneous pregnancies). This may be explained by an over-correction of earlier studies, which excluded all unkaryotyped miscarriages. In three out of 42 amniocenteses, translocation trisomies 13 were diagnosed (7.1 +/- 4.0% of all amniocenteses). The frequency of stillbirths was 3.3 +/- 1.6% for female carriers and 1.4 +/- 1.4% for male carriers. A low risk for the live birth of translocation trisomy 13 children was confirmed since no live born children with trisomy 13 or Pätau syndrome were detected in the ascertainment-corrected sample.

Autosomal dominant polycystic kidney disease (ADPKD) usually becomes symptomatic between the third and fifth decades. We studied ten families segregating for ADPKD in which children were observed with typical manifestations of the disease at birth or in early childhood. In these families, linkage analysis was carried out with a cloned DNA sequence from the alpha-globin locus known to be closely linked to the disease gene in adult onset ADPKD. In the families studied here, close linkage (theta max = 0.09 at zmax = 2.32) was also observed between the marker and disease loci. These results provide no evidence for genetic heterogeneity of ADPKD in families with early and adult onset.

We report a new case of Johanson-Blizzard syndrome. The clinical findings with special reference to the dentition are discussed, and the literature is reviewed. The reported case underlines the heterogeneity of ectodermal dysplasias mentioned by Freire-Maia (1971).

Autosomal recessive polycystic kidney disease (ARPKD) is the most common pediatric renal cystic disease with liver involvement. The vast majority of patients with ARPKD carry mutations in the recently characterized PKHD1 gene on chromosome 6p12. A Turkish female demonstrated rapid growth of both kidneys after delivery. Accelerated growth of both kidneys and increasing respiratory distress necessitated right-sided nephrectomy at the age of three months. Because of persistent dyspnea and ongoing growth of the remaining kidney, the second kidney also had to be removed one month later. Biopsies taken from the kidney and the liver confirmed the diagnosis of ARPKD histologically. Renal ultrasound of the patient's consanguineous parents and her older brother showed normal results. PKHD1 mutation analysis yielded a novel homozygous missense mutation (c.1116C >G, F372L) in exon 14, coding for an Ig-like domain (TIG), possibly involved in the increased growth of the kidneys. Peritoneal dialysis was performed for 12 months. The patient had successful transplantation at the age of 15 months and is doing well with actual immunosuppression with cyclosporine, mycophenolate mofetil, and prednisolone. In conclusion, the present case clearly demonstrates the favorable outcome of a child with severe ARPKD after bilateral nephrectomy, pre-emptive dialysis, and successful transplantation.

Small heat shock proteins prevent abnormal protein folding and accumulation. We analyzed the expression of hsp27 and alphaB-crystallin in skeletal muscle specimens of patients with desminopathies, plectinopathies, myotilinopathy, and other myofibrillar myopathies by means of differential centrifugation, 2D-gel electrophoresis, Western blotting, and mass spectrometry. Hsp27-P82 and -P15 as well as alphaB-crystallin-P59 and -P45 are the major serine phosphorylation isoforms in normal and diseased human skeletal muscle. 2D-gel-electrophoresis revealed spots of hsp27 in a range of pH 5.3-6.4 in samples of all skeletal muscle specimens, except for the seven desminopathies. They indicated a shift of the main hsp27-spot to alkaline pH degrees, which may help to differentiate primary desminopathies from other myopathies with structural pathology of the desmin cytoskeleton.

Due to the poor prognosis of severe autosomal recessive polycystic kidney disease (ARPKD), there is a strong demand for prenatal diagnosis (PD). Reliable PD testing is possible by molecular genetic analysis only. Although haplotype-based analysis is feasible in most cases, it is associated with a risk of misdiagnosis in families without pathoanatomically proven diagnosis. Linkage analysis is impossible in families where DNA of the index patient is not available. Direct mutation analysis of the recently identified polycystic kidney and hepatic disease 1 gene opens new options in families to whom a reliable PD cannot be offered on the basis of linkage analysis. We for the first time report two cases with PD based on mutation detection, illustrating the new options for PD in ARPKD.

Desbuquois dysplasia is a rare chondrodysplasia of autosomal recessive inheritance characterized by short stature, joint laxity, facial anomalies, a "Swedish key" appearance of the proximal femur, and advanced carpal and tarsal bone age. Patients with Desbuquois dysplasia can be divided in two groups, depending on whether hand changes include an extra ossification center distal to the second metacarpal and whether phalangeal dislocations are present or absent. We have recently reported linkage of a Desbuquois dysplasia gene to 17q25.3 in a group of patients with typical hand abnormalities. Here, we report on the exclusion of the 17q25.3 locus in three inbred Desbuquois families originated from Turkey, Asia, and Morocco without typical hand abnormalities. Microsatellite DNA markers from the 17q25.3 region were used at an average spacing of 2 cM, and the three affected individuals from families 1 to 3 were heterozygous for the 17q25.3 region. These results allow us to exclude this region as the locus in Desbuquois families with no hand anomalies and demonstrate genetic heterogeneity. Ongoing studies will hopefully lead to the identification of the responsible genes.

Autosomal recessive spinal muscular atrophy with respiratory distress type 1 (SMARD1) is the second anterior horn cell disease in infants in which the genetic defect has been defined. SMARD1 results from mutations in the gene encoding the immunoglobulin mu-binding protein 2 (IGHMBP2) on chromosome 11q13. Our aim was to review the clinical features of 29 infants affected with SMARD1 and report on 26 novel IGHMBP2 mutations. Intrauterine growth retardation, weak cry, and foot deformities were the earliest symptoms of SMARD1. Most patients presented at the age of 1 to 6 months with respiratory distress due to diaphragmatic paralysis and progressive muscle weakness with predominantly distal lower limb muscle involvement. Sensory and autonomic nerves are also affected. Because of the poor prognosis, there is a demand for prenatal diagnosis, and clear diagnostic criteria for infantile SMARD1 are needed. The diagnosis of SMARD1 should be considered in infants with non-5q spinal muscular atrophy, neuropathy, and muscle weakness and/or respiratory distress of unclear cause. Furthermore, consanguineous parents of a child with sudden infant death syndrome should be examined for IGHMBP2 mutations.

Background Recent studies found a relationship between Vitamin D and atherosclerosis. A common genetic polymorphism of the Vitamin D receptor (VDR) has been associated with coronary artery disease (CAD) in small study populations. To assess its influence on the prevalence and severity of CAD we studied a large-scale population. Methods A total of 3441 consecutive patients were referred for diagnostic coronary angiography. The BsmI Vitamin D receptor polymorphism was analyzed by polymerase chain reaction. Angiography was used to define phenotypes with clear coronary arteries (n = 775), coronary sclerosis (diameter stenosis 50% in at least one vessel; n = 1524). Patients with CAD at a young age (females aged less than 65 years, males aged less than 55 years; n = 563) were specially defined as premature CAD. The risk profile of traditional cardiovascular risk factors was obtained for every patient. Results The genotype frequencies of the VDR BsmI polymorphism did not differ between all four phenotypes (P = 0·756). The allele frequencies for the B allele were 0·43 vs. 0·44 vs. 0·42 vs. 0·45 in the four phenotypic groups (P = 0·827). All traditional cardiovascular risk factors (hypercholesterolaemia, smoking, hypertension, diabetes mellitus, severe obesity, male gender) were significantly (P

Mutations in the human caveolin-3 gene (cav-3) on chromosome 3p25 have been described in limb girdle muscular dystrophy, rippling muscle disease, hyperCKemia, and distal myopathy. Here, we describe the genetic, myopathological, and clinical findings in a large German family harboring a novel heterozygous mutation (GACGAA) in codon 27 of the cav-3 gene. This missense mutation causes an amino acid change from asparagine to glutamate (Asp27Glu) in the N-terminal region of the Cav-3 protein, which leads to a drastic decrease of Cav-3 protein expression in skeletal muscle tissue. In keeping with an autosomal dominant mode of inheritance, this novel cav-3 mutation was found to cosegregate with neuromuscular involvement in the reported family. Ultrastructural analysis of Cav-3–deficient muscle showed an abnormal folding of the plasma membrane as well as multiple vesicular structures in the subsarcolemmal region. Neurological examination of all nine subjects from three generations harboring the novel cav-3 mutation showed clear evidence of rippling muscle disease. However, only two of these nine patients showed isolated signs of rippling muscle disease without muscle weakness or atrophy, whereas five had additional signs of a distal myopathy and two fulfilled the diagnostic criteria of a coexisting limb girdle muscular dystrophy. These findings indicate that mutations in the human cav-3 gene can lead to different and overlapping clinical phenotypes even within the same family. Different clinical phenotypes in caveolinopathies may be attributed to so far unidentified modifying factors/genes in the individual genetic background of affected patients. Ann Neurol 2003

Pontocerebellar hypoplasia (PCH) is rarely associated with anterior horn cell disease and designated as PCH-1. This phenotype is characterized by severe muscle weakness and hypotonia starting prenatally or at birth with a life span not exceeding a few months in most cases. Milder disease courses with later onset and longer survival are normally not diagnosed as PCH-1. We describe the clinical and neuroradiological findings in nine patients out of six siblingships with evidence of cerebellar defects and early onset spinal muscular atrophy (SMA), representing a broad spectrum of clinical variability. In all patients, the diagnosis of SMA (Werdnig-Hoffmann disease) was made on the basis of electrophysiological data and muscle biopsy; however, genetic testing failed to confirm the diagnosis of infantile SMA with a gene defect on chromosome 5q and resulted in clinical reevaluation. Age at onset was after a normal period in the first months of life in three siblingships and pre- and postnatally in the other three families. Life span was 2–4 years in patients with later onset, and age at death occurred after birth or within months in the more severe group. Two siblingships showed discordant ages at death despite similar treatment. In contrast to the previous definition of PCH-1, our observations suggest the existence of milder phenotypes with pontocerebellar hypoplasia or olivopontocerebellar atrophy in combination with anterior horn cell loss. A pontine involvement is not necessarily seen by neuroimaging methods. The genetic basis of PCH-1 remains to be determined. The gene locus for infantile SMA on chromosome 5q could be excluded by linkage studies. Parental consanguinity and affected siblings make autosomal recessive inheritance most likely. © 2002 Wiley-Liss, Inc.

Autosomal recessive polycystic kidney disease (ARPKD) is an often devastating form of polycystic kidney disease that presents primarily in infancy. The locus, PKHD1 (polycystic kidney and hepatic disease 1), on chromosome 6p21.1-p12, has been linked to all classical forms of this disorder. In previous studies, we cloned the PKHD1 interval in a set of overlapping YACs, converted this YAC-based framework into a BAC/PAC contig, and delimited the critical interval to a region flanked by the markers D6S1714 and D6S1024. We now have refined the genetic interval using new polymorphic markers developed from our BAC/PAC resources. In addition, we have evaluated a recently identified, EF hand-containing gene that maps to the interval of interest, established its transcript sequence, defined its genomic organization, and excluded this new gene as a PKHD1 candidate. Therefore, this study has narrowed the PKHD1 interval and excluded a potentially relevant gene as a PKHD1 candidate gene. This further refinement of the PKHD1 interval will facilitate efforts to identify the PKHD1 gene by positional cloning. These data also provide additional, highly polymorphic markers for haplotype-based diagnostic testing for ARPKD.

Objective To assess the rate and type of urinary incontinence in a large sample of children and adolescents with spinal muscular atrophy (SMA), a genetic disorder characterized by loss of motor function caused by anterior horn degeneration. Patients, subjects and methods The study included 96 severely incapacitated patients with SMA (aged 6.0–18.11 years) who were examined in detail, including a structured interview (Kinder-DIPS), the Child Behaviour Checklist (CBCL) and a specific questionnaire for urinary incontinence. They were compared with two control groups of unaffected siblings and normal children. Results In all, 29% of the patients were wet at night and/or during the day; mostly younger children with SMA types I and II only were affected. The results of the interview were more reliable than the CBCL. The specific questionnaire revealed a variety of possible functional and neurogenic forms of wetting, including nocturnal enuresis, voiding postponement, dysfunctional voiding, stress, symptomatic (urinary tract infections, UTIs) and neurogenic incontinence. Many patients were constipated, soiled or had UTIs. The rate of behavioural problems was twice as high (32%) as normal (15%; CBCL). Conclusion Children with SMA have a high rate of urinary incontinence which is often overlooked, and not diagnosed and treated adequately. These problems should be addressed routinely by paediatricians in children referred to paediatric urological specialists.

In 1993, we described an autosomal-dominant syndrome in a German family characterized by ectrodactyly/syndactyly, dysplasia of nails, lacrimal duct atresia, hypodontia, hypoplastic breasts and nipples, intensive freckling (ADULT syndrome, acro-dermato-ungual-lacrimal-tooth syndrome, MIM 103285). In 1996 a large Dutch family with an autosomal-dominant syndrome ("limb mammary syndrome", LMS, MIM *603543) characterized by hypoplasia/aplasia of mammary glands and nipples, ectrodactyly, other hand/foot anomalies, lacrimal-duct atresia, nail dysplasia, hypohidrosis, cleft palate/bifid uvula, hypodontia was reported. In this family the disease locus was recently mapped to the chromosomal region 3q27 through a genome-wide linkage screen. Given the similarity of manifestations we hypothesized that the two syndromes might be allelic. We genotyped 21 members of the ADULT family with 19 polymorphic markers from the chromosomal region 3q27 and obtained a maximal lod score of 4.82 at straight theta = 0.00 with marker D3S1288. Our results place the ADULT locus to the same chromosomal region where LMS was mapped, suggesting that these two conditions are allelic.

We report on two sibs, both males, one born at 37 the other at 24 weeks of gestation, both with a syndrome similar to that seen in three sets of sibs by Gillessen-Kaesbach et al. [1993: Am J Med Genet 45:511–518]. Both propositi had polycystic kidneys and hepatic fibrosis indistinguishable from that seen in autosomal recessive polycystic kidney disease (ARPKD), and skeletal and facial anomalies. Skeletal abnormalities included “butterfly” vertebrae, square shape of pelvis, and brachymelia. The facial anomalies included hypertelorism, epicanthic folds, and anteverted nares. Additional external findings were apparently low-set ears and a short neck. Histopathological examination of the kidneys showed radial orientation and cystic dilatation of the cortical and medullar tubules. The liver showed “congenital hepatic fibrosis.” The hepatic findings in the second infant were less severe. Renal abnormalities were limited to focal tubular cystic changes. Linkage analysis with polymorphic markers of the region 6p21.1-p12, flanking the gene locus of ARPKD, showed different haplotypes in the sibs, thus excluding the ARPKD gene locus in this family and indicating genetic heterogeneity. Am. J. Med. Genet. 90:115–119, 2000 © 2000 Wiley-Liss, Inc.

Autosomal recessive polycystic kidney disease (ARPKD) is one of the most common hereditary renal cystic diseases and has a high infant mortality. Prenatal diagnosis using fetal sonography can be unreliable, especially in early pregnancy. The ARPKD locus has been mapped to proximal chromosome 6p allowing haplotype-based prenatal diagnosis in "at-risk" families. From December 1994 to March 1997, we received 258 inquiries regarding prenatal evaluation and we have completed analyses in 212 families. To date, 65 prenatal analyses have been performed in 57 families. In the majority of the requesting families (45/57), the index children are deceased and their DNA was extracted from paraffin-embedded tissue. Eighteen fetuses were homozygous for the disease-associated haplotypes. In 12 of these fetuses, pathoanatomical examination demonstrated typical ARPKD changes consisting of dilated collecting ducts and the characteristic hepatic ductal plate malformation. These changes were detected in two fetuses as early as 13 weeks gestational age. These cases represent the earliest demonstration of ARPKD-associated histopathology reported to date. One high risk fetus was carried to term and turned out to be unaffected. However, the diagnosis of ARPKD remained doubtful in the index patient. Forty-three fetuses were either heterozygous or homozygous for a nondisease-associated haplotype and all infants born were phenotypically unaffected at birth. In four cases, a recombination event occurred between the flanking markers and no genotypic prediction was possible. Three of these pregnancies were terminated and necropsy of the fetuses confirmed ARPKD, while one fetus was carried to term and showed no abnormalities at birth. These results show that haplotype-based prenatal testing is feasible and reliable in pregnancies "at risk" for ARPKD. An absolute prerequisite for these studies is an accurate diagnosis of ARPKD in previously affected sib(s).

Three newborn siblings presented with generalized weakness, asphyxia, facial diplegia, and external ophthalmoplegia. Electrophysiological testing showed inexcitability of motor and sensory nerves and myographic signs of denervation. Nerve biopsies and postmortem examination showed loss of myelinated fibers and axonal damage in sensory and mixed nerves. Many spinal motor neurons were chromatolytic although their number was normal. Molecular genetic investigations revealed a homozygous deletion of the survival motor neuron (SMN) gene and a loss of markers Ag1-CA and C212 in the paternal haplotype. These findings are consistent with the diagnosis of an unusually severe type of spinal muscular atrophy. Given the large extent of the deletion, it must be considered that the unusual severe phenotype with involvement of brainstem nuclei and afferent nerves might also be due to changes of yet unknown genes neighboring the SMN gene.

The clinical course of 66 boys and 49 girls with autosomal recessive polycystic kidney disease recruited from departments of paediatric nephrology was investigated over a mean observation period of 4.92 years. This is a selected study group of children from departments of paediatric nephrology who in most cases survived the neonatal period, since birth clinics did not participate. The median age at diagnosis was 29 days (prenatal to 14.5 years). We observed decreased glomerular filtration rates (GFRs) in 72% (median age at onset of decrease of GFR < 2 SD, 0.6 years; range, 0-18.7 years), and 11 patients developed end-stage renal disease. Hypertension requiring drug treatment was found in 70% (median age at start of medication, 0.5 years; range, 0-16.7 years). Kidney length was above the 97th centile in 68% of patients, and kidney length did not increase with age or deterioration of renal function. Urinary tract infections occurred in 30%, growth retardation in 25%, and clinical signs of hepatic fibrosis were detected in 46%. Thirteen patients (11%) died during the observation period, 10 of them in the first year of life. There was a statistically significant sex difference in terms of a more pronounced progression in girls. The survival probability at 1 year was 94% for male patients and 82% for female patients (p < 0.05) in this study. Urinary tract infections occurred more frequently in girls (p < 0.025) and were observed earlier. In addition, more girls had impaired renal function, developed end-stage renal disease and showed growth retardation; these differences, however, were not significant. For the children in this study, however, our results indicate that the long-term prognosis in the majority of cases is better throughout childhood and youth than often stated.

Prenatal prediction in families at risk for autosomal recessive proximal spinal muscular atrophy (SMA) mainly of type I is often requested due to the high incidence and the fatal outcome of the disease. So far, only indirect genotype analysis can be performed in SMA families, since the gene has not yet been identified. We present our experience of 109 prenatal diagnoses obtained in 91 families by use of single- and multi-locus polymorphic microsatellites of the region 5q11.2–q13.3. The marker combinations and specific features of the closest microsatellites are described in detail. From 137 requests for prenatal prediction of SMA between October 1991 and August 1994, 28 families were excluded, mostly because the clinical diagnosis was uncertain or doubtful. Others had to be classified as ‘SMA-variants’ or showed autosomal dominant transmission of SMA. Of the 109 prenatal diagnoses performed, 29 fetuses were diagnosed to be at high risk (>99 per cent) of developing the disease, while in seven additional pregnancies no exact prediction could be made due to a recombination event in one parental haplotype. Altogether, recombinations between closely flanking markers were observed in 14 cases. In 35 cases, the parents decided to terminate the pregnancy. Of the remaining pregnancies, 32 could be followed beyond term. All infants were reported to develop normally without signs of SMA. Two children were born with transverse reduction defects of one hand, which was most likely related to early chorionic villus sampling at 9 and 10 weeks' gestation. No further abnormalities could be detected. The limits of indirect genotype analysis and the problems of diagnostic accuracy and heterogeneity of proximal SMA are discussed.

We describe a family with at least seven living persons who are affected by an hitherto undescribed autosomal-dominant syndrome with variable expression, bearing close resemblance to the EEC syndrome and related disorders. The main manifestations are hypodontia and/or early loss of permanent teeth, ectrodactyly, obstruction of lacrimal ducts, onychodysplasia, and excessive freckling. We propose the acronym ADULT (acro-der-mato-ungual-lacrimal-tooth)-syndrome for this condition. © 1993 Wiley-Liss, Inc.

The first case of isochromosome 18p as a mosaic in a male fetus diagnosed by amniocentesis is reported. After termination of the pregnancy at 21 weeks gestation biopsies from different fetal organs as well as from the placenta were taken and set up for long term cell cultures. The distribution of the normal and abnormal cell-line in fetal organs was unequal. Unexpectedly the metaphases in the placenta and the lymphocyte culture all showed a normal karyotype. The tetrasomy 18p is associated with a uniform phenotype, even in fetal life, characterized by a small head with protuberant occiput, low-set ears with posterior rotation, epicanthic fold, sharp pinched nose, convex and poorly formed philtrum, high-arched palate, retrognathia, flexion contractures of fingers, short and broad hallux, hypoplastic penis, angulation of clavicles and mild scoliosis. The propositus showed no growth retardation.

We report on two brothers and one sister with achalasia and alacrimia born to consanguineous unaffected parents. The combination of achalasia and alacrimia may represent an entity different from the triple-A syndrome in showing normal adrenal function.