Biomedical subjects
Publications and source records attributed to J M Opitz.
Excluding environmental, psychotic, and unclassified categories, a total of 1,231 cases of severe mental retardation were found in the Central Wisconsin Center study. Some 45% of cases were estimated to be genetically caused or predisposed, but in only 15% was the risk of recurrence considered high. Nevertheless, I feel strongly that parents of all retarded patients deserve etiologic/diagnostic counseling.
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On the basis of 3 personal observations and of 6 cases from the literature, two peculiar types of enchondromatosis are delineated: 1. Enchondromatosis with generalized, irregular vertebral lesions, and 2. Generalized enchondromatosis with mild platyspondyly.
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We report two patients with a similar syndrome of gross malformation of a lower limb and contiguous structures due to involvement with dysplastic, teratomatous tissue. This dysplasia seems to have arisen in a paramedian position in the embryonic hindquarter at the time of lower limb-bud differentiation. Malignant degeneration at 5--7 months led to metastases and death in both cases around 1 year of age. The behavior of the dysplastic/oncoplastic tissue suggests a 2-"mutational" causal model. This is an apparently previously undescribed formal genesis syndrome.
This paper is an introduction to the cytogenetic biology of man. It deals with the role of chromosome abnormalities in prenatal death, malformation syndromes, mental retardation, malformation/mental retardation syndromes, abnormalities of sex determination, sex differentiation and sexual function, cancer, and certain genetic disorders in which chromosome abnormalities are seen commonly. Down syndrome is discussed as an important and common example of a malformation/mental retardation syndrome.
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A 15 year old boy with the Fanconi malformation-aplastic anemia syndrome developed erythroleukemia and died of multiple arterial thromboses and hemorrhage. He was one of 10 siblings including 3 affected sisters. He was short of stature and had hypoplastic thumbs; his testes were small and secondary sexual characteristics were inadequately developed. At autopsy he was found to have very few spermatogonia, i.e., a histological picture compatible with the "Sertoli-cell-only" defect. Male hypogonadism in other chromosome breakage syndromes (the Bloom syndrome and ataxia telangiectasia) may have a similar pathogenesis.
We reviewed the SC phocomelia syndrome (SCS) and the Roberts syndrome (RS) to demonstrate techniques of nosologic analysis based primarily on the phenotype analysis. We considered type, localization, severity, and variability of the manifestations. In this patient sample these techniques are not sensitive enough to rule out any one of the three most likely etiologic hypotheses, namely whether the SCS and the RS are due to different recessive genes, different alleles, or the same recessive gene. However, this study does suggest certain implications for each of these possibilities.
We describe a boy with the hypertelorism-hypospadias (BBB) syndrome. His mother and his maternal grandmother showed minor manifestations suggestive of the syndrome. The BBB syndrome is a syndrome of multiple congenital anomalies with mental retardation due a segregating mendelian mutation, either X-linked or autosomal. This paper reviews the literature on the subject and emphasizes the problem of identifying females at high risk of transmitting the condition.
The family history of 40 patients with severe "pure" mental retardation (MR) was studied to determine the incidence of mental retardation and dull-normal intelligence among relatives, probable etiologies and an empiric recurrence risk. Significant findings include: (1) an increased sex ratio (69% males) of propositi, (2) a significant proportion of patients with clinical manifestations besides MR, (3) virtually no consanguinity among parents, (4) a "positive" family history for over 1/2 of the propositi--about 37% of all children in the sibships were affected; about 21% of the full sibs were affected, (5) a higher number of offspring produced by dull persons and a lower number of offspring from retarded persons compared to two normal persons (6) a proportionately large number of affected children produced from matings involving one or two dull persons, (7) a tendency for dull to have additional dull children and mentally retarded parents to have further retarded children while normal parents with more than one affected child usually had further retarded children, (8) an incidence of affected parents of about 32%, and (9) an overall empiric recurrence risk of 14%. Several etiologies were discussed as possible causes of the condition(s) in this group: (unrecongized) environmental damage and/or maternal/fetal interaction; unrecognized chromosome abnormalities; the homozygous state of several different autosomal recessive gees: X-linked recessive mutations; autosomal dominat new mutations; and mutifactoral inheritance. It was concluded that the group was etiologically heterogeneous and although none of the probable etiologies could be excluded, it seemed reasonable to assume that autosomal recessive inheritance plays an important role in the etiology of severe "pure" mental retardation.
Bilateral testicular biopsies in an 81/2 year old boy with the Prader-Willi syndrome showed total absence of spermatogonia. Similar findings in postpubertal cases (Wannarachue et al., 1975) suggest that testicular dysplasia is one of the reasons for hypogonadism in males with the Prader-Willi syndrome.
A 10 year old girl with a mental age of 7-8 years, normal height and head circumference and several minor anomalies had hemiasymmetry of the entire body, the left side being uniformly smaller than the right. The smaller side was considered the abnormal side and her condition interpreted as hemihypotrophy on the basis of a chromosome abnormality which involved mosaicism, with lymphocytes showing a balanced but very unequal translocation of most of 13q transferred to 7p and both translocation chromosomes being present, and all examined fibroblasts lacking the small translocation chromosome and hence being monosomic for 13p, proximal part of 13q and a terminal portion of 7p.
The gross and microscopic eye findings in the first historic case of the 13-trisomy syndrome included: severe microphthalmia, coloboma of the ciliary body, cataracts, detached retina, and retinal dysplasia.
Siblings are reported with severe mental retardation, spastic cerebral palsy and seizures; in addition they had progressive or intermittent jaundice and recurrent infections; they died at 3 and 4 years respectively. Neuropathological studies in one showed a small brain with an almost complete lack of myelin in cerebral white matter, brain stem, cerebellum and anterolateral parts of the spinal cord. The condition most likely represents a dysgenesis of myelin (dysmyelination), possibly due to an inability of oligodendrocytes to form myelin and/or metabolic defects in the process of myelination. This mental retardation condition is probably inherited as an autosomal recessive trait and may represent a special type of a primary CNS developmental defect.