摘要:

AbstractWe report on a group of 9 subjects who had a 46, XY karyotype, ambiguous genitalia, abnormalities of sexual duct formation, and lack of gonadal tissue on one or both sides. This is sometimes referred to as “embryonic testicular regression.” Previous investigators have suggested that this condition results from loss of testes at a critical stage in development. We examined the possibility that the “embryonic testicular regression” is part of the clinical spectrum of 46, XY gonadal dysgenesis.Four subjects totally lacked gonadal tissue, three of them having ambiguous genitalia, and one a micropenis. The development of incongruous sexual ducts (presence of Müllerian ducts in the subject with micropenis, and absence of Müllerian and Wolffian ducts in two subjects with ambiguous genitalia) suggests that the embryonic gonads were intrinsically functionally abnormal before their disappearance.Five subjects had unilateral gonadal tissue, ambiguous genitalia, and a mix of Wolffian and Müllerian structures. The development of incongruous sexual ducts in 3 of them, the presence of ambiguous external genitalia in 5, and the presence of abnormal gonadal histology in 2 patients all indicate an underlying abnormality of gonadal differentiation in these subjects.The occurrence of testicular regression in several subjects in the family of one patient suggests a genetic basis for the condition. The presence of multiple congenital anomalies in other subjects in our study suggests either a mutation in a single gene that functions in several developmental pathways, or a defect of multiple genes that might be the result of a chromosome deletion. The sex‐determining region Y (SRY) gene was sequenced in five subjects and was normal in all of them, suggesting that the underlying genetic abnormality in these subjects is located in one of several genes that function subsequent to SRY in the early stages of testis differentiation. © 1994 Wi

ISSN:0148-7299    

DOI:10.1002/ajmg.1320490102

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1994

数据来源: WILEY

摘要:

AbstractWe describe the ultrasound findings of polycystic pancreas with short rib dwarfism in the early second trimester. Radiologic, morphologic, and histologic examination after pregnancy termination confirmed the findings and also disclosed dysplastic kidneys. The skeletal anomalies are similar to those in Verma Naumoff type of short rib polydactyly, but the extraskeletal malformations have never been reported before in this syndrome. © 1994 Wiley‐Liss, I

ISSN:0148-7299    

DOI:10.1002/ajmg.1320490103

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1994

数据来源: WILEY

摘要:

AbstractRare genetic diseases have been reported with high frequency in some populations. The mechanisms which were proposed to explain most of these observations include founder effect, genetic drift or selective advantage. In recent years, many genes have been sequenced and mutations causing some of these disorders were characterized. According to the analysis of haplotypes and/or mutations, it may be possible to distinguish 3 groups of disorders frequent in isolated populations. In the first group, all the affected patients have only one frequent mutation, suggesting a founder effect with genetic drift. In the second group, more than one mutation is found among the patients; however, most of the patients are homozygotes for one frequent mutation which most probably originated from a common founder; the other patients are compound heterozygotes for the common mutation and a rare mutation. In the third group, more than one frequent mutation is found responsible for each disease. This may be due to a selective advantage which allows the expansion of each new mutation in the particular population or to multiple founder effect with genetic drift in smaller communities which thereafter mixed to form the larger population. © 1994 Wiley‐Liss, I

ISSN:0148-7299    

DOI:10.1002/ajmg.1320490104

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1994

数据来源: WILEY

ISSN:0148-7299    

DOI:10.1002/ajmg.1320490105

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1994

数据来源: WILEY

ISSN:0148-7299    

DOI:10.1002/ajmg.1320490106

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1994

数据来源: WILEY

ISSN:0148-7299    

DOI:10.1002/ajmg.1320490107

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1994

数据来源: WILEY

摘要:

AbstractStarting from a data base of over one million births investigated in 11 countries as a part of the Latin American Study of Congenital Malformations, 1,428 babies with three or more malformations without known pathogenesis or cause were studied. The objective was to search for statistically significant associations between defects and the delineation of new syndromes. One hundred and twentyone patients presented an association between malformations of the digestive and urogenital systems involving mainly anal, renal, and genital anomalies, while 21 of them had 3 or more VACTERL defects. The frequencies of these defects were intermediate between those observed for VACTERL or sirenomelia, supporting the idea that these conditions have a similar pathogenesis. Statistical approaches like this one may be helpful in identifying processes and biological entities that may be missed using simple clinical observations. © 1994 Wiley‐Liss, I

ISSN:0148-7299    

DOI:10.1002/ajmg.1320490108

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1994

数据来源: WILEY

摘要:

AbstractOpitz has defined developmental field defects (DFD) as “any dysmorphogenetically reactive unit of the developing organism that leads to final structure.” We have incorporated in our coding system specific codes to identify individual DFDs in each child, irrespective of the cause or type of the MCA pattern (i.e., chromosomal, mendelian, environmental, or unknown). Using this approach, we can analyze the group of defects included in the expression of each DFDas a discrete unit.To confirm our hypothesis that vertebral and rib anomalies constitute a DFD, we have studied all of our cases with segmentation anomalies of the spine and ribs, including hemivertebrae, fused or absent vertebrae, and “crab‐like” thorax, all of which fall into the loosely defined groups of spondylothoracic dysplasia, costovertebral dysplasia, Jarcho‐Levin syndrome, and others. The study was performed using the 18,743 malformed children from the ECEMC data files, 110 of them having vertebral/rib anomalies. © 1994 Wil

ISSN:0148-7299    

DOI:10.1002/ajmg.1320490109

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1994

数据来源: WILEY

摘要:

AbstractLubinsky [1986: Am J Med Genet 2:9–16] has defined associations as derivatives of causally nonspecific disruptive events acting on developmental fields. Opitz [1992: Second International Workshop on Fetal Genetic Pathology]considers developmental fields as the basic biologic units of individual development and of evolution, and has stated that associations represent the idiopathic occurrence of multiple congenital anomalies during blastogenesis. These concepts imply that associations represent the concurrence of a greater number of developmental field defects (DFDs) than other patterns of multiple anomalies.The coding system for children with multiple congenital anomalies, developed in the Spanish Collaborative Study of Congenital Malformations (ECEMC), permits analysis of DFDs as morphogenetic units. Thus, we can study their presence in any type of MCA pattern, regardless of its etiology.Here we present the analysis of a selected group of DFDs of blastogenic origin. Specifically, we have studied how the groups of defects, usually comprised in those specifics DFDs, are observed in children who present different clinical entities such as associations, embryopathies, syndromes of known etiology, and others. The results of our analysis show a greater concurrence of the selected DFDs in associations than in other MCA pattern, and support the concept of Lubinsky [1985: Am J Med Genet 21:35–38; 1986] and Opitz [1992]. © 1994 Wiley‐Lis

ISSN:0148-7299    

DOI:10.1002/ajmg.1320490110

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1994

数据来源: WILEY

摘要:

AbstractLimb deficiency defects (LD) occurring among 1,575,904 births in Hungary during 1975–1984 were reviewed. The overall birth prevalence of LD was 1 in 1,816. This paper discusses the nature and distribution of the limb and other defects in the 275 (32%) children who had structural malformations in other systems. Two main forms of classification were used: morphologic and causal.Additional malformations were most commonly seen in infants with amelia, rudimentary limb (RL), radial/tibial (RT), intercalary or central axis (CA) LD and rarely in those with terminal transverse (TT) or ulnar/fibular (UF) defects. Upper limbs (81%) were involved significantly more often than lower limbs (42%) and there were more right‐sided defects (83% vs. 71%) due to an excess of right arm involvement especially with radial ray and split hand anomalies. Single limb involvement was relatively common withy amelia (88%), UF (82%), RT (50%), and TT defects. With other LD, multimelic involvement was more characteristic. This was usually symmetric with Ca anomalies and digital deficiencies (DD).From a causal perspective, 17% of cases had genetic disordes, 52% had recognized associations, anomalies, sequences, environmental causes or patterns of unknown origin, and 31% had unknown patterns of malformations. The commonest entities were amnion disruption sequence (16% of cases) and VACTERL association (8%). Both of these disorders showed unusual temporal distribution.As anticipated, patterns of malformations differed with the type of LD. Amelia and digital amputations were often seen with body wall defects, atypical anencephaly or encephalocele, and cleft lip reflecting amnion disruption. Rudimentary limb was seen with anencephaly, omphalocele, renal agenesis, aberrant genitalia, and imperforate anus, reflecting defects of blastogenesis including the cloacal exstrophy and caudal regression sequences and Schisis association. Radial/tibial defects were associated with different patterns depending on whether the limp defects were unilateral or bilateral. Unilateral defects occurred with anomalies suggesting VACTERL association or the facio‐auriculo‐vertebral anomaly, while bilateral defects occured more often in genetic or potentially genetic disorders including VACTERL with hydrocephalus. Central axis defects showed three main patterns of association: one reflecting the ectrodacyly‐ectodermal dysplasia‐clefting syndrome; one with tongue anomalies representing a variant of oro‐mandibular‐limb (Hanhart) anomaly, and the last with hydronephrosis indicating a group of “acrorenal” syndromes. Strong associations with other anomalies were not seen in the grups with TT, UF, or intercalary defects. ©

ISSN:0148-7299    

DOI:10.1002/ajmg.1320490111

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1994

数据来源: WILEY