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Short stature, myopia, severe developmental delay, and peculiar facial appearance in two brothers: a new syndrome?

We report on 2 brothers with short stature, microcephaly, myopia, retarded osseous maturation, severe developmental delay, and minor anomalies including temporal narrowing, periorbital fullness, full cheeks in infancy, and protruding lower lip. Both brothers and their parents had normal chromosomes. Fluorescence in situ hybridization with probes from all (sub-)telomeric chromosomal regions excluded a structural rearrangement involving telomeric segments. Because the pattern of congenital abnormalities is not like that of any well-known multiple congenital anomaly/mental retardation syndrome, we suggest a previously undescribed syndrome of autosomal recessive or X-linked inheritance.

Adult↗

Cri du chat syndrome: changing phenotype in older patients.

The cri du chat syndrome or 5p deletion syndrome is a well-delineated clinical entity and has an incidence of 1/50,000 in newborn infants. A de novo deletion is present in 85% of the patients. Ten to 15% are familial cases with more than 90% due to a parental translocation and 5% due to an inversion of chromosome 5. Although the size of the deleted segment varies, the critical segment that is deleted in all patients appears to be 5p15.2. The clinical picture is well known in younger patients and includes the typical high-pitched cry, psychomotor retardation, microcephaly, growth rate failure, and craniofacial abnormalities including round face, hypertelorism, broad nasal bridge, downward slanting palpebral fissures, and micrognathia. With advancing age, the clinical picture becomes less striking. We present seven patients with 5p deletion syndrome, who were between age 16 and 47 years. Comparing their phenotype at several ages, a change of their phenotype was noted. Some of the clinical characteristics became more evident such as long face, macrostomia, and scoliosis. All patients were severely or profoundly mentally retarded except one patient who was mildly mentally retarded. The diagnosis was difficult to make in some of the patients who were first seen at an older age. In some of them, the craniofacial appearance resembled that seen in Angelman syndrome. Most patients had periods of destructive behavior, self mutilation, and aggression. The clinical diagnosis should be confirmed as soon as possible with cytogenetic investigation to provide specific support, prevention, and treatment of complications. Therefore, it is important to perform follow-up studies in young children to determine their outcome after infant-stimulation programs.

Adolescent↗

Molecular cytogenetic studies in three patients with partial trisomy 2p, including CGH from paraffin-embedded tissue.

We report on three cases of partial trisomy 2p in which the identification and exact localization of the duplicated chromosome segment was possible only by application of molecular cytogenetic techniques. These included fluorescence in situ hybridization by use of wcp2, N-myc, and subtelomeric 2p probes and comparative genomic hybridization with DNA isolated from blood samples, frozen fetal tendon, and formalin fixed, paraffin-embedded fetal lung tissue. Two of the cases concerned fetuses of gestational week 20 and 24 with duplication of nonoverlapping terminal (2pter-->p24) and more proximal (2p25-->p23) segments and with distinctly different phenotypes. The third case was due to a de novo inverted duplication of 2p25-->p23, with loss of the subtelomeric region of 2p. This 53-month-old girl was a Bloom syndrome carrier. The patient had prenatal growth failure, borderline microcephaly, dilated lateral horns of the cerebral ventricles, transient cortical blindness, myopia, muscle hypotonia, and dilatation of the left renal collecting system. Dermal cysts were found on the glabella, the soles of both feet, and the vocal cord, causing respiratory embarrassment. Previously reported cases of pure trisomy 2p are reviewed, in an attempt to correlate clinical findings to overlapping regions in 2p. These cases illustrate the effectiveness of molecular cytogenetic methods in resolving subtle chromosomal aberrations in order to coordinate more accurately a chromosome regionspecific phenotype.

Abortion, Induced↗

Neural tube defects and the 13q deletion syndrome: evidence for a critical region in 13q33-34.

Neural tube defects (NTD) are common findings in the 13q deletion syndrome, but the relationship between the 13q- syndrome and NTDs is poorly understood. We present a child with a 13q deletion and lumbosacral myelomeningocele. This was a boy with microcephaly, telecanthus, minor facial anomalies, and ambiguous genitalia. Cytogenetic and fluorescence in situ hybridization analysis showed a de novo 46,XY,del(13)(q33.2-->qter) with no visible translocation. By using microsatellite markers, the deletion breakpoint was mapped to a 350-kb region between D13S274 and D13S1311 and was paternal in origin. An analysis of 13q deletions with NTDs, including the present case, suggests that a deletion in 13q33-34 is sufficient to cause an NTD. The deletions associated with NTDs are distal to and nonoverlapping with the previously defined critical region in 13q32 for the major malformation syndrome [Brown et al., 1999: Am J Hum Genet 57: 859-866]. Our analysis also suggests that one or more genes in 13q33-34 produces NTDs by haploinsufficiency.

Abnormalities, Multiple↗

Phenytoin-induced alterations in craniofacial gene expression.

In utero exposure to the anticonvulsant drug phenytoin has been shown to alter normal embryonic development, leading to a pattern of dysmorphogenesis known as the Fetal Hydantoin Syndrome. This embryopathy is characterized by growth retardation, microcephaly, mental deficiency, and craniofacial malformations, although the precise mechanism(s) by which phenytoin alters normal developmental pathways remains unknown. To better understand the molecular events involved in the pathogenesis of phenytoin-induced congenital defects, alterations in gene expression were examined during critical periods of craniofacial development. Pregnant SWV mice were administered phenytoin (60 mg/kg/day) from gestational day 6.5 until they were sacrificed at selected developmental time points. Tissue from the craniofacial region of control and exposed embryos was isolated, and samples were subjected to in situ transcription, antisense RNA amplification, and hybridization on reverse Northern blots to quantitatively assess expression of 36 candidate genes. Chronic phenytoin exposure significantly altered expression of several genes at distinct times during morphogenesis. Results of these studies show that expression of the retinoic acid receptors (RAR) alpha, beta, and gamma were significantly increased by phenytoin exposure. Elevations in gene expression of laminin beta 1, and the growth factors IGF-2, TGF alpha, and TGF beta 1, were also demonstrated in the craniofacial region of phenytoin-exposed embryos. As several of these genes are transcriptionally regulated by retinoic-acid-responsive elements in their promoter regions, phenytoin-induced alterations in expression of the RAR isoforms may have severe downstream consequences in the regulation of events necessary for normal craniofacial development. Such alterations occurring coordinately at critical times during craniofacial development may account for the dysmorphogenesis often associated with phenytoin exposure.

Abnormalities, Drug-Induced↗

Discussion: severe mental retardation and cancer among atomic bomb survivors exposed in utero.

When I was in medical school, Douglas Power Murphy, Professor of Obstetrics and Gynecology, told us of his inexpensive, simple study of "microcephaly" and mental retardation in newborn infants whose mothers had received therapeutic radiation early in pregnancy. His review of the literature and mail inquiry of other obstetrics centers in the United States revealed 14 published cases (Murphy, '28) and 16 unpublished (Goldstein and Murphy, '29). Here am I, 52 years later, still updating his findings.

Adult↗

Central nervous system in twin reversed arterial perfusion sequence with special reference to examination of the brain in acardius anceps.

The twin-reversed arterial perfusion (TRAP) sequence, or acardia, is the most severe complication in monozygotic twinning. Although more than 400 cases with TRAP sequence were reported since 1533, thorough investigations of the brain in those cases with a rudimentary head remained infrequent. We report a TRAP sequence with microcephaly and a severely rudimentary brain anlage. Neuropathologic examination clearly demonstrated two types of change: (1) developmental arrest of brain at the prosencephalic stage (holoprosencephaly), and (2) hypoxic damage to the holospheric brain mantle with cystic change (hydranencephaly). With reference to previous studies in experimental animals showing that lack of oxygen during early embryogenesis can induce severe disruptions of head-brain and heart formation, it is concluded that oxygen deficiency due to TRAP may be responsible not only for the encephaloclastic changes in the acardius anceps, but for the developmental arrest of the brain cases as well. This would make it unnecessary to postulate additional primary causes such as asymmetric zygote cleavage (Schwalbe, '07) for the maldevelopment.

Abnormalities, Multiple↗

Prenatal diagnosis of partial monosomy 3p and partial trisomy 2p in a fetus associated with shortening of the long bones and a single umbilical artery.

The prenatal and postnatal findings of a fetus with partial deletion of 3p25 -> pter and duplication of 2p25.3 -> pter are described. The proband postnatally displayed mental and growth retardation, psychomotor delay, microcephaly, ptosis, micrognathia, a narrow palate, and cryptorchidism. All of these anomalies were consistent with those described in 3p- and partial trisomy 2p syndromes, and also frequently seen in patients with other chromosomal disorders. However, the prenatal sonograms revealed unusual shortening of the long bones, a single umbilical artery, and normal development of the skull. Our case suggests that skeletal growth retardation of the long bones may occur earlier than that of the skull in fetuses associated with chromosomal aberrations such as del(3p)/dup(2p). Shortening of the long bones and a single umbilical artery together with other abnormalities detected by prenatal ultrasound thus warrant a fetal cytogenetic study.

Abnormalities, Multiple↗

Prenatal diagnosis of ring chromosome 6 in a fetus with hydrocephalus.

A patient with ring chromosome 6/monosomy 6 mosaicism is presented. At 25 weeks' gestation, ultrasound examination demonstrated fetal hydrocephalus. Amniocentesis was performed. The fetal karyotype was 45,XY,-6/ 45,XY,-6,+f/46,XY,r(6)(p25q27). Delivery of this male infant was by Caesarean section at 37 weeks' gestation. The karyotype in peripheral blood lymphocytes was 46,XY,r(6)(p25q27) with no indications of mosaicism. The infant had hydrocephalus which required treatment with a ventriculoperitoneal shunt at 22 days of age. He had no other obvious serious congenital anomalies. By 17 months he had developed microcephaly, seizures, severe bilateral hearing loss, and global development delay. This patient provides information regarding phenotypic variability of ring chromosome 6 and also reinforces the importance of offering amniocentesis if fetal hydrocephalus is detected as an isolated anomaly.

Adolescent↗

A paternally inherited terminal deletion, del(8)(p23.1)pat, detected prenatally in an amniotic fluid sample: a review of deletion 8p23.1 cases.

A subtle terminal deletion of the short arm of chromosome 8 with a breakpoint in p23.1 was detected in amniocytes. Parental chromosome studies revealed a similar deletion in the father. The fetus did not have any abnormalities in a level II ultrasound. The pregnancy was continued and resulted in the birth of a baby girl. The child was normal at six months of age and no heart murmur was detected. In a retrospective review of cases in our laboratory, four other cases with a deletion del(8)(p23.1) were found. Three were paediatric cases with microcephaly, developmental delay, ASD, VSD, pulmonic stenosis, congenital and behavioural abnormalities. One was a 29-year-old woman with a mosaic karyotype. She had a history of spontaneous abortions and no known cardiac defect. Using conventional cytogenetics and/or FISH studies with 8p telomere probe and 8 painting probe, the 8p23.1 deletions were shown to be either terminal or interstitial. The karyotype from the prenatal case was compared with the other cases of 8p23.1 deletions in our laboratory to see if there was a discernible difference in the size of the deletion. The deletion in the proband seemed to involve a more distal 8p23.1 breakpoint. In the father's high resolution chromosomes (550-850 band level) the breakpoint appeared to be 8p23.1 approximately 23.2 and FISH studies using an 8p telomeric probe confirmed a terminal deletion. Interstitial deletion of sub-band 8p23.1 was associated with phenotypic abnormalities and distal 8p23.2pter deletion was found in apparently normal individuals, therefore, 8p23.1 appears to be the critical region for clinical abnormalities.

Adult↗

Prenatal diagnosis of a fetus with a cryptic translocation 4p;18p and Wolf-Hirschhorn syndrome (WHS).

Wolf-Hirschhorn Syndrome (WHS) is caused by distal deletion of the short arm of chromosome 4 and is characterized by growth deficiency, mental retardation, a distinctive, 'greek-helmet' facial appearance, microcephaly, ear lobe anomalies, and sacral dimples. We report a family with a balanced chromosomal translocation 4;18(p15.32;p11.21) in the father and an unbalanced translocation resulting in partial monosomy 4 and partial trisomy 18 in one living boy and a prenatally diagnosed male fetus. Both showed abnormalities consistent with WHS and had in addition aplasia of one umbilical artery. Karyotyping of another stillborn fetus revealed a supernumerary derivative chromosome der(18)t(4;18)(p15.32;p11.21) of paternal origin and two normal chromosomes 4. The umbilical cord had three normal vessels. A third stillborn fetus with the same balanced translocation as the father had a single umbilical artery and hygroma colli.

Abnormalities, Multiple↗

Novel de novo nonsense mutation of MECP2 in a patient with Rett syndrome.

Because of the recent identification of several mutations of methyl-CpG-binding protein 2 (MECP2) in patients with Rett syndrome (RTT), a patient with suspected RTT from an autism clinic was screened for mutations. She was found to have a novel heterozygous nonsense mutation, 129C>T (Q19X), which leads to the most severely truncated MECP2 protein reported to date. Sequencing of parental DNA revealed the mutation was de novo. The patient was not affected with microcephaly or hyperventilation, but had other features of Rett syndrome including severe mental retardation and symptoms of autistic disorder. Moderately skewed X-chromosome inactivation (XCI) may have contributed to her relatively mild phenotype.

Base Sequence↗

Determination of the frequency of the common 657Del5 Nijmegen breakage syndrome mutation in the German population: no association with risk of breast cancer.

Nijmegen breakage syndrome (NBS) is an autosomal recessive chromosomal instability syndrome characterized by microcephaly, growth retardation, immunodeficiency, and cancer predisposition. It shares a number of features with the Ataxia telangiectasia (AT) syndrome: the most notable are high sensitivity to ionizing radiation and predisposition to cancer. Recently, the gene responsible for NBS has been identified on chromosome band 8q21. It encodes a DNA double-strand break repair protein, named Nibrin. A truncating 5-bp deletion (657Del5) has been identified in 90% of NBS patients and this is presumed to be of Slavic origin. There is evidence that heterozygous AT mutation carriers are predisposed to breast cancer. Since the NBS phenotype at the cellular level is very similar to AT, we have screened 477 German breast cancer patients, aged under 51 years, and 866 matched controls for the common NBS mutation. We have identified one carrier among the cases and one among the controls, indicating that the population frequency of this NBS mutation is 1 in 866 people (95% CI = 1 in 34,376 to 1 in 156) and the estimated prevalence of NBS is thus 1 in 3 million people. The proportion of breast cancer attributable to this mutation is less than 1%. Genes Chromosomes Cancer 25:393-395, 1999.

Breast Neoplasms↗

Prenatally diagnosed hypoplastic left heart syndrome--outcomes after postnatal surgery.

OBJECTIVE: To identify prenatally diagnosed cases of hypoplastic left heart syndrome (HLHS) and then to determine postnatal outcomes after surgical interventions. METHODS: An ultrasound and pediatric cardiology database was used to identify all fetuses diagnosed prenatally from 1991-1996 with HLHS. Fetal karyotypes were performed on cultured amniocytes. After diagnosis, parents were given several management options: pregnancy termination before 22 weeks, postnatal hospice care, or surgery using the Norwood procedure or cardiac transplantation. Ultrasound and echocardiography findings were later compared to karyotype results and postnatal outcome data. RESULTS: Fifteen fetuses with HLHS were identified. Two (16%) chromosome abnormalities and three (20%) structural defects were detected. Three mothers (20%) opted for pregnancy termination, two (13%) chose postnatal hospice care, and one aneuploid fetus had an intrauterine death. Nine parents (60%) chose surgery for their infants; however, one infant was not an appropriate surgical candidate due to a coexisting diaphragmatic hernia. Eight infants underwent surgery and two survived (25%). Of the four infants scheduled to undergo the Norwood procedure, one died preoperatively, two died intraoperatively, and one infant survived and is doing well at age 8 months. Of the four infants scheduled for cardiac transplantation, two died awaiting transplant and one died postoperatively. One infant survived cardiac transplantation but has microcephaly and developmental delay at age two. CONCLUSIONS: In prenatally diagnosed HLHS at our institution, the survival rate following surgery for infants felt to be the best candidates was only 25%.

Abortion, Legal↗

Paternal UPD15: further genetic and clinical studies in four Angelman syndrome patients.

Among 25 patients diagnosed with Angelman syndrome, we detected 21 with deletion and 4 with paternal uniparental disomy (UPD), 2 isodisomies originating by postzygotic error, and 1 MII nondisjunction event. The diagnosis was obtained by molecular techniques, including methylation pattern analysis of exon 1 of SNRPN and microsatellite analysis of loci within and outside the 15q11-q13 region. Most manifestations present in deletion patients are those previously reported. Comparing the clinical data from our and published UPD patients with those with deletions we observed the following: the age of diagnosis is higher in UPD group (average 7 3/12 years), microcephaly is more frequent among deletion patients, UPD children start walking earlier (average age 2 9/12 years), whereas in deletion patients the average is 4 (1/2) years, epilepsy started later in UPD patients (average 5 10/12 years) than in deletion patients (average 1 11/12 years), weight above the 75th centile is reported mainly in UPD patients, complete absence of speech is more common in the deleted (88.9%) than in the UPD patients because half of the children are able to say few words. Thus, besides the abnormalities already described, the UPD patients have somewhat better verbal development, a weight above the 75th centile, and OFC in the upper normal range.

Angelman Syndrome↗

Growth charts for cri-du-chat syndrome: an international collaborative study.

Low birth weight and slow growth are frequently observed in the patients with cri-du-chat syndrome. To provide a growth reference standard for children with cri-du-chat syndrome, syndrome-specific growth charts have been developed from a combination of cross-sectional and longitudinal measurements on 374 patients from North America, Italy, Australia, and the British Isles. The data were obtained from pediatric records, parent reporting, and personal examinations at national 5p- parent support group meetings in the U.S., Italy, U.K., and Australia. The growth curves include height and weight measurements for patients ages 0 to 18 years and head circumference measurements for patients ages 0 to 15 years. Birth weight was above the 5th percentile of general population in 50% of cases: mean weight 2.8 kg +/- 1.85 SD for males and 2.6 kg +/- 1.51 SD for females. Growth curve medians were usually at or below the 5th centile of reference populations throughout life. The median head circumference falls below the 2nd centile, and this change increases with age. The charts show that compared with the standard population, most children with cri-du-chat syndrome are small at birth and as they grow most, but not all, have significant microcephaly and compromised weight for age, and to a lesser extent, compromised height for age. Am. J. Med. Genet. 94:153-162, 2000.

Adolescent↗

Further case of aminopterin syndrome sine aminopterin in a Spanish child.

We report on a Spanish child with clinical manifestations suggestive of aminopterin syndrome sine aminopterin (ASSA), having unusual hair pattern, syndactyly of fingers and toes, low-set thumbs, high-arched palate, and mild developmental delay. However, he does not show other characteristic features of ASSA such as ossification defects of the cranium, microcephaly, hypertelorism, cryptorchidism, or growth retardation. Differences from and similarities with Juberg-Hayward syndrome are discussed. Because few patients have been reported so far it is difficult to distinguish between these two conditions, and it may be that they are variants of the same nosological entity. Consanguinity of parents in this family supports autosomal recessive inheritance of ASSA.

Abnormalities, Multiple↗

Functional disomy for Xq26.3-qter in a boy with an unbalanced t(X;21)(q26.3;p11.2) translocation.

A nine-month-old boy, with functional disomy for Xq26-qter and multiple congenital abnormalities, is reported. The boy had severe pre- and postnatal growth retardation, profound developmental delay, hypotonia, microcephaly, agenesis of the corpus callosum, dysmorphic facial features, cryptorchidism, and left multidysplastic kidney. He developed feeding difficulties and infantile spasms. G-banding analysis of his chromosomes showed additional material on the short arm of chromosome 21. His parents refused to submit to chromosome analysis. Analysis with chromosome microdissection followed by reverse and forward chromosome painting indicated his karyotype as 46,XY,der(21)t(X;21)(q26;p11.2). This is the first description of pure functional disomy for Xq26-qter due to an unbalanced X-autosome translocation.

Abnormalities, Multiple↗