A translocation interrupts the COL5A1 gene in a patient with Ehlers-Danlos syndrome and hypomelanosis of Ito.

Ehlers-Danlos syndrome (EDS) is a genetically and pathogenetically heterogeneous group of disorders of which at least 11 types have been described. All are connective tissue disorders characterized by defects of the skin, ligaments and blood vessels with the clinical spectrum ranging from innocuous findings to lethality. Mutations in the genes encoding the major fibrillar collagen types I and III have been demonstrated in EDS types VII and IV, respectively, while mutations in the lysyl hydroxylase and ATP7A genes, with roles in collagen cross-linking, are responsible for EDS types VI and IX. The biochemical and molecular bases for the most common forms of EDS (types I, II and III) are unknown. Here, we describe a balanced translocation between chromosome 9 and an X chromosome that disrupts the minor fibrillar collagen type V gene COL5A1 in a patient with both EDS type I and hypomelanosis of Ito. The breakpoint occurs at 9q34 within COL5A1 intron 24 and interestingly, within a LINE-1 (L1) element at Xp21.1. A fusion mRNA between COL5A1 and an Alu sequence is produced, but no aberrant protein is detectable. Rather, the amount of type V collagen is reduced in the patient's fibroblasts, suggesting haploinsufficiency as a cuase of the phenotype. This demonstrates that a mutation in a type V collagen gene, COL5A1, results in EDS type I, and shows the involvement of L1 sequences in a constitutional chromosomal translocation. Because collagen type V is a heteromorphic protein in which molecules may be composed of polypeptides encoded by three COL5A genes, this suggests all three genes as candidates for mutations in EDS.

Nonrandomness of translocations in man: preferential entry of chromosomes into 13-15-21 translocations.

Lymphocytes from 20 individuals with Down's syndrome due to 13-15/21 centric-fusion translocations were studied by autoradiography after continuous late labeling with tritiated thymidine. In no case was chromosome 13 involved; chromosome 14 was involved in 18 cases, and chromosome 15 in two cases. These results are similar to those from 13 previously studied cases and indicate that the entry of chromosomes 13-15 into translocations is nonrandom. This nonrandomness is not a simple function of chromosome size or shape, since chromosomes 13-15 are acrocentrics of similar size.

Ovarian dysgenesis due to 45 X, 0/46 dic (X) mosaicism.

A 16 year old girl was evaluated for short stature, primary amenorrhea, and lack of development of secondary sex characterisics. She did not have the classical phenotypic signs of Turner's syndrome. However, she was short, had infantile genitalia and the adnexa were not palpable. There was a minor bone malformation and no signs of visceral abnormalities. The hormonal studies showed hypergonadotropic hypogonadism and borderline hypothyroidism. The rest of the endocrine functions was normal. The Barr bodies on the buccal smear were decreased and in part abnormal, large or bipartite. The karyotype showed mosaicism of about equal proportions of 45 X, 0/46, X, dic (X). The large dicentric chromosome was due to the end to end fusion of two X chromosomes by their short arms. Sequential binding studies were performed and failed to document any loss of genetic material of the dicentric X. It is speculated that the fusion of X chromosomes during an early mitotic division was responsible for the 45 X, U cell line, and that the short stature and gonadal dysgenesis in this patient was due to the presence of the 45 X, 0 line.

Craniodigital syndromes: report of a child with Filippi syndrome and discussion of differential diagnosis.

We describe a boy with low birth weight, congenital microcephaly, multiple minor facial anomalies, cleft palate, soft tissue syndactyly of fingers and toes, and moderate to severe mental retardation. Literature review suggested 6 possible diagnoses, including Scott craniodigital syndrome, Chitayat syndrome, Filippi syndrome, Zerres syndrome, Kelly syndrome, and Woods syndrome. Each has as part of the phenotype craniofacial anomalies and soft tissue syndactyly of fingers and toes; and superficially, distinction among the 6 may be difficult. However, based on the phenotype analysis we performed, we conclude that our patient has Filippi syndrome, and thus is the first reported case from the United States.

Occurrence of neural tube defects among first-, second-, and third-degree relatives of probands: results of a United States study.

Data on the occurrence of neural tube defects in first-, second-, and third-degree relatives of probands were collected in a United States study. The proportions of affected individuals were 3.2%, 0.5%, and 0.17% respectively. These findings are compared to those from other recent North American studies, and differences are discussed. It is pointed out that accurate recurrence risk figures may not be available, and that caution should be used when counseling families with relatives who are affected with NTD.

Possible causal heterogeneity in spina bifida cystica.

A study was performed to determine whether causal heterogeneity can be demonstrated among the nonsyndromal spina bifida cysticas based on the vertebral level of the defect. Two groups were compared, probands with defects at or above T 11, likely representing defects of neuralization, and probands with defects at or below T 12, likely defects of canalization. Differences between the two groups were found with respect to reproductive history and occurrence of other malformations. A high degree of concordance for the type of defect among affected sib pairs was also observed. These findings indicate that there is probably heterogeneity within the spina bifida cysticas based on the level of the defect.

X-linked midline defects.

Opitz and Gilbert [Am J Med Genet 12:443-455, 1982] have postulated that the midline may be a kind of developmental field. Although developmental field defects (primary malformations) usually occur sporadically, in some instances they can be caused by a single gene mutation. We report on a family in which the occurrence of midline defects was consistent with X-linked inheritance. Anomalies present in the family include hydrocephalus, anencephaly, cleft lip, congenital heart defect, renal agenesis, and hypospadias.

Provisionally unique autosomal recessive chondrodysplasia punctata syndrome.

Stippled epiphyses occur in several monogenic, teratogenic, or aneuploidy syndromes. We describe two sibs with a provisionally unique chondrodysplasia punctata syndrome, who have, in addition to stippled epiphyses, minor facial anomalies, short stature, and ocular colobomata. Inheritance of this condition is likely autosomal recessive.

Menkes syndrome in a girl with X-autosome translocation.

We report on a girl with Menkes syndrome (M.S.) and X-2 reciprocal translocation. We conclude that the probable locus for M.S. gene is at band Xq13. This case and other previous case reports of X-linked disorders in females suggest that chromosome analysis is indicated in all females who present with manifestations of a known X-linked lethal condition in order to detect a possible associated balanced X-autosome translocation.

Two siblings with Tel Hashomer camptodactyly and mitral valve prolapse.

A brother and sister with Tel Hashomer camptodactyly and mitral valve prolapse are described. Mitral valve prolapse is heterogenous, but appears to occur more frequently in individuals with connective tissue disorders. The presence of mitral valve prolapse as a component manifestation of Tel Hashomer camptodactyly suggests that abnormal connective tissue is a pleiotropic effect of the mutant allele.

Renal tubular dysgenesis: delayed onset of oligohydramnios.

Two premature sibs had Potter sequence and died of respiratory failure within the first day. Ultrasonography at 26 weeks during the earlier of the two pregnancies showed complete absence of amniotic fluid, and the urinary bladder was not visualized. Ultrasound examinations during the second pregnancy showed adequate amniotic fluid at 16 and 20 weeks, with a subsequent reduction in fluid volume. Two older sibs had also died of respiratory failure shortly after birth. Postmortem histopathologic studies showed all four sibs to have severely deficient renal tubular development. However, the presence of numerous glomeruli indicated prolific nephrogenesis. Most of the tubules in sections of cortex had the lectin-binding and immunohistochemical characteristics of collecting ducts; proximal tubules were not identified by lectin-binding. Electron-microscopic examination showed a general absence of differentiated characteristics in cortical tubular epithelium, except that rare tubules contained rudimentary proximal tubular brush borders. Three of the sibs were boys, one a girl. The three children that were studied had normal chromosomes. Two unaffected sibs are alive and well. Neither parent has any clinical evidence of renal disease. These studies support the interpretation that renal tubular dysgenesis is autosomal recessive with pleiotropy. However, the relatively late appearance of oligohydramnios makes early diagnosis difficult, even when the condition is suspected.

Sibs with the fetal akinesia sequence, fetal edema, and malformations: a new syndrome?

Pena and Shokeir [J Pediatr 85:373-375. 1974] first described a syndrome characterized by multiple ankyloses, camptodactyly, facial anomalies, and pulmonary hypoplasia, which was later termed Pena-Shokeir I syndrome. Recent evidence suggests that a more accurate designation for this condition is the fetal akinesia sequence, which is almost certainly a heterogeneous entity. We describe sibs who were diagnosed as having Pena-Shokeir I syndrome but who did not have the muscular or anterior horn cell changes characteristic of other infants with the fetal akinesia sequence. In addition, both sibs had fetal edema, the first sib had coarctation of the aorta, and the second had polydactyly and thyroid hypoplasia. We suggest that this case provides further evidence for heterogeneity in the fetal akinesia sequence and may represent a provisionally unique syndrome.

Familial occurrence of a developmental defect of the medial nasal processes.

We report on a family in which the propositus and two distant relatives have a wide nose, broad philtrum, and short columella, a fusion defect of the medial nasal processes. This anomaly resembles potato nose [Benjamins and Stibbe, Acta Otolaryngol 11:274-284, 1927] and bifid nose [Anyane-Yeboa et al, Am J Med Genet 17:561-563, 1984], which are also fusion anomalies of the medial nasal processes. Potato nose is an autosomal dominant trait, whereas bifid nose is likely heterogeneous. In this family autosomal recessive inheritance is likely, therefore suggesting that anomalies of the medial nasal processes are causally heterogeneous and represent a developmental field defect.

An apparently new syndrome of microcephalic primordial dwarfism and cataracts.

We describe two sibs with prenatal-onset growth deficiency, microcephaly, cataracts, mental retardation, enamel hypoplasia, immune deficiency, and generalized delay of ossification. The combination appears to constitute a previously undescribed autosomal recessive syndrome.

Brief clinical report: ring-11 chromosome: phenotype-karyotype correlation with deletions of 11q.

The cytogenetic evaluation of a female infant with congenital anomalies led to the identification of the second reported case of a ring-11 chromosome. Unlike the previously described case, in which the patient had only minimal clinical findings and no demonstrable loss of material from the ring, our patient had numerous anomalies that were associated with a substantial deficiency of 11q material. The different phenotypes in these two cases represent variation in the amount and location of the chromosomal material lost during the genesis of the ring. The manifestations of this patient and the deletion of region q24 leads to qter from the ring-11 identify a specific chromosome deletion syndrome referred to as del (11q) syndrome.

Report of a case and further delineation of the SHORT syndrome.

We describe a boy with the manifestations of the SHORT syndrome: lipoatrophy, delayed speech development, minor facial anomalies, clinodactyly, and short stature. In addition, this boy had deafness, which was not previously reported in the SHORT syndrome.

Pulmonary and diaphragmatic agenesis: report of affected sibs.

We report on two sibs with pulmonary and diaphragmatic agenesis, a rare combination of malformations. We conclude that this represents a previously undescribed autosomal recessive condition affecting either multiple developmental fields or a single complex polytopic field.

X-linked syndrome of branchial arch and other defects.

We report on two brothers and their maternal first cousin who have branchial arch defects and other anomalies. Similar physical findings in all three include microcephaly, downslanting palpebral fissures, highly arched palate, apparently lowset, protruding ears, bilateral hearing loss, slightly webbed neck, and mild short stature. In addition, two boys had cryptorchidism, and one had subvalvar pulmonic stenosis and body asymmetry. We suggest that these cousins have an X-linked syndrome of which branchial arch defects are a component. Other pleiotropic manifestations of the mutant gene include microcephaly and cryptorchidism; body asymmetry and relatively short stature may be components as well.

Prenatal diagnosis of Smith-Lemli-Opitz syndrome, type II.

Smith-Lemli-Opitz syndrome, type II (SLOS-II) is a severe autosomal recessive disorder characterized by a distinctive face, unusual cleft palate, postaxial polydactyly, congenital heart defects, renal anomalies, and male pseudohermaphroditism. We present the first report of prenatal diagnosis of SLOS-II, as well as an additional report of prenatal detection of multiple anomalies, in which a positive diagnosis of SLOS II was made postnatally. In neither case was the pregnancy known prospectively to be at risk for SLOS-II. In the former case, targeted sonographic examination at 31 weeks of gestation showed intrauterine growth retardation, atrioventricular septal defect, mesomelic shortening of the arms, small kidneys, overlapping fingers, and female external genitalia; a 46,XY chromosome constitution had been ascertained previously. A provisional diagnosis of SLOS-II was made prenatally. In the latter case, targeted sonographic examination at 18 weeks of gestation showed severe oligohydramnios, atrioventricular septal defect, and Dandy-Walker malformation. The kidneys and bladder were not visualized. The chromosome constitution was 46,XX. The diagnosis of SLOS-II was made postnatally. In both cases, additional findings compatible with SLOS-II were noted postnatally. Prenatal detection of congenital heart defects and renal abnormalities, in combination with certain additional findings (most notably, female external genitalia in the presence of a 46,XY karyotype, polydactyly, disproportionately short limbs, or intrauterine growth retardation) and a normal karyotype, suggests the diagnosis of SLOS-II, and warrants further investigation.

DiGeorge anomaly in an infant with deletion of chromosome 22 and dup(9p) due to adjacent type II disjunction.

A term white girl presented with low birth weight, minor anomalies, and congenital heart defects. The infant had microcephaly, upslanting palpebral fissures, prominent nasal bridge, short philtrum, thin upper lip vermilion, down-turned corners of the mouth, receding mandible, and short broad neck. The hands showed proximal placement of the thumbs, bilateral clinodactyly of the index finger, and bilateral transverse crease. Both hands were clenched, with the index finger overlapping the third finger and the fifth finger overlapping the fourth. There was also talipes calcaneo-valgus, bilateral dorsiflexion of the metatarsophalangeal joints, flexion of the interphalangeal joints, and hypoplasia of all nails. The patient's karyotype was 46,XX,-22, + der(9)t(9;22)(q21.13;q12.1)mat; the mother had the balanced translocation 46,XX,t(9;22)(9pter----9q21.13::22q12.1----22qter++ +;22pter---- 22q12.1::9q21.3----9qter). The infant died at age 10 days, and the autopsy showed absent thyroid isthmus and rudimentary thymus, with one small ectopic parathyroid attached to it. The lungs were hypoplastic, with abnormal lobation. The cardiac anomalies included truncus arteriosus, truncal valve stenosis, single carotid trunk, subclavian arteries arising from the distal part of the aortic arch, atrial and ventricular septal defects, right ventricular hypertrophy, and a hypoplastic left pulmonary artery. Also, multiple small accessory spleens were present in addition to a normal-sized spleen. This case combines features associated with DiGeorge anomaly and dup(9p). The chromosome abnormality in this patient appears to have arisen in a maternal germ cell due to adjacent type II disjunction.