Comparison of rhesus and cynomolgus macaques as an infection model for COVID-19

A novel coronavirus, SARS-CoV-2, has been identified as the causative agent of the current COVID-19 pandemic. Animal models, and in particular non-human primates, are essential to understand the pathogenesis of emerging diseases and to assess the safety and efficacy of novel vaccines and therapeutics. Here, we show that SARS-CoV-2 replicates in the upper and lower respiratory tract and causes pulmonary lesions in both rhesus and cynomolgus macaques. Immune responses against SARS-CoV-2 are also similar in both species and equivalent to those reported in milder infections and convalescent human patients. This finding is reiterated by our transcriptional analysis of respiratory samples revealing the global response to infection. We describe a new method for lung histopathology scoring that will provide a metric to enable clearer decision making for this key endpoint. In contrast to prior publications, in which rhesus are accepted to be the preferred study species, we provide convincing evidence that both macaque species authentically represent mild to moderate forms of COVID-19 observed in the majority of the human population and both species should be used to evaluate the safety and efficacy of interventions against SARS-CoV-2. Importantly, accessing cynomolgus macaques will greatly alleviate the pressures on current rhesus stocks.

The association between non-diabetic hyperglycaemia and incident vascular disease

Background

It is unknown whether the associated risk of vascular disease for individuals with non-diabetic hyperglycaemia (NDH) persists following the Type 2 diabetes (T2D) diagnosis. We assessed whether NDH detection before the T2D diagnosis is associated with different risk of incident vascular disease following the T2D diagnosis.

Methods

Population-based retrospective cohort study including 159,736 individuals with newly diagnosed T2D from the CPRD database in England between 2004 and 2017. Outcomes: incident retinopathy, nephropathy, and composite macrovascular disease. We employed time-partitioned Cox regression models partitioning the 10-year follow-up period into 4 equal time segments to model differences in rates between groups with different glycaemic status in the 3 years before diagnosis of T2D.

Results

Following T2D diagnosis those with prior NDH had 86%, 58%, and 42% increased rates of retinopathy in the 30 months, between 31 and 60 months, and 61 and 90 months, respectively(0-30 months: HR 1.86,95%CI 1.69-2.04;31-60 months: HR 1.58,95%CI 1.37-1.84;61-90 months:HR 1.42,95%CI 1.10-1.83), as compared with those with prior normoglycaemia. They also had 16% and 25% increased rates of nephropathy in the period 0-30 months and 31-60 months, respectively (0-30 months: HR 1.16,95%CI 1.07-1.26;31-60 months: HR 1.25,95%CI 1.09-1.42). Individuals with prior NDH had 19% reduced rate of macrovascular disease in the first 30 months of the study period (HR 0.81,95%CI 0.71-0.93), as compared with individuals with glycaemic values within the normal range.

Conclusions

Individuals detected with NDH had increased rates of microvascular disease up to 7.5 years following the diagnosis of T2D. Timely testing and identification of NDH and specific clustering of NDH with other risk factors for T2D might prompt earlier risk factor assessment and tailored vascular risk reduction strategies during the NDH phase to reduce the burden of vascular disease following the diagnosis of T2D

Key messages

Individuals detected with NDH had increased rates of microvascular disease up to 7.5 years following the diagnosis of T2D, as compared with individuals with prior normoglycaemia. Timely detection of NDH and specific clustering with other risk factors for T2D might prompt earlier and tailored vascular risk reduction strategies to reduce the burden of vascular disease.

Assessment of an electron-impact GC-MS method for organic acids and glycine conjugates in amniotic fluid

We assessed the reliability of a method designed for common electron-impact GC-MS systems to determine in a single run most organic acids and glycine conjugates of clinical interest in amniotic fluid. Suitable sensitivity was achieved by dividing the selected-ion chromatogram into 12 time segments during which the monitoring dwelt on specific ions. Twelve metabolites were simultaneously quantified in amniotic fluid, with performances ranging from very good to clinically acceptable. The total coefficient of variation was 2.5-14.1% and the detection limit was well below the lower value of the physiological range. For five other metabolites, the precision was lower and/or the detection limit was near the physiological range. The method was clinically assessed by the prenatal detection of three cases of tyrosinaemia type I and one case of propionic acidaemia. Analytical and clinical evaluation of the method showed that GC-MS with electron-impact fragmentation can be an informative analytical approach for low-level organic acids in physiological fluids. Apart from the case of glycine conjugates, the method shows a fair reliability for amniotic fluid analysis, which might warrant its use for prenatal diagnosis of organic acidurias. However, this method cannot replace procedures using isotopic internal standards, nor GC-MS based on chemical ionization fragmentation, which remain confirmatory analytical methods of choice.

[Medical genetics service]

Created in 1987, the department of medical genetics finds its origins in molecular endocrinology research which had developed from the seventies at the Institut de Recherche Interdisciplinaire en Biologie Humaine et Moléculaire (IRIBHM) of the Faculty of Medicine. After its fusion with the Center of Human Genetics of the ULB, in 1992, the department is composed of three units: the lab of molecular genetics and oncology, the lab of cytogenetics and a clinical genetics unit. One thousand consultations of genetic counseling and more than 15,000 molecular or cytogenetic diagnostic procedures are performed annually. The development of the clinical activities was paralleled by a very active research activity, resulting in a series of "firsts". Amongst the main results are: the identification of the first mutations responsible for congenital hypothyroidism; the molecular cloning of the TSH receptor and of a series of "orphan" G protein-coupled receptors; the identification of a novel neuropeptide, nociceptin, by the first example of "reverse pharmacology"; the identification of olfactory receptors on the sperm of mammals, including man; the identification in molecular terms of the mechanisms responsible for acquired and hereditary hyperthyroidisms; the identification of the chemokine receptor CCR5 as the major coreceptor of HIV-1, and of the prevalent mutation of CCR5 conferring resistance to HIV to about 1% of the European population.

[Individual genetic counseling and collective screening strategies in particular at-risk populations]

Carrier screening for recessive disorders together with prenatal diagnosis offered in at risk pregnancies can achieve efficient prevention of genetic diseases occurring with particularly high frequencies in specific populations. In this context, genetic counseling, which should be available to each at risk couple, must be integrated into a more elaborate framework geared towards informing the target population. Dramatically different outcomes of carrier screening programmes implemented in the past illustrate the conditions for success or failure. The need to target selected ethnic groups accounts for most of the problems encountered: underpriviledged minorities, risk of discrimination and, most importantly, cultural gaps leading to refusal of prenatal diagnosis and/or of selective abortion. In order to achieve prevention through screening programmes, the tests should therefore be preceded by dissemination of adequate information into the target population, followed by genetic counseling for at risk couples, addressing cultural differences. Prenatal diagnosis should always be proposed, but never imposed on these couples. Finally, these screening programmes must be underpinned by comprehensive subsidies covering not only the tests but also education and counseling that should always be provided with the tests. In terms of public health, this is the price for a cost-effective genetic screening programme.

Preimplantation genetic diagnosis for medium-chain acyl-CoA dehydrogenase (MCAD) deficiency

Medium-chain acyl-CoA dehydrogenase (MCAD) deficiency is the most common defect in fatty acid oxidation. The disease is inherited in an autosomal recessive fashion (carrier frequency around 1 in 70) and probably affects as many as 1 in 10000 new-borns. Affected children usually present within the two first years of life with recurrent episodes of hypoketotic hypoglycaemia and lethargy leading to death in approximately 25% of the cases. One mutation (c985A-->G) accounts for approximately 90% of the carrier chromosomes. We developed a preimplantation genetic diagnosis (PGD) strategy for MCAD for a couple who had already lost two affected children. When tested on heterozygous lymphoblasts, the amplification efficiency was 67 out of 71 (94%) and the allele drop-out rate was 0 out of 67. The patient became pregnant after one PGD cycle during which two embryos were replaced. The twin pregnancy was checked by chorionic villus sampling (CVS) and was shown to be unaffected. The twins have been born and are healthy.

Further evidence for autosomal dominant inheritance and ectodermal abnormalities in Kabuki syndrome

Most cases with Kabuki syndrome (KS) were reported sporadically. Recently, a few familial cases of KS were reported. This report provides further evidence that the KS is inherited as a dominant trait with variable expressivity. The proposita is an 18-month-old girl with facial findings characteristic of Kabuki syndrome, prominent fingertip-pads, a midsagittal cleft of vertebral body D4, hypotonia, and psychomotor retardation. Her mother had a similar facial appearance, prominent, cup-shaped ears, an abnormal dentition, early breast development, and low-normal intelligence. Because mother and daughter both had evident Kabuki syndrome, we conclude that KS in this family is inherited as a dominant trait. Further family history supports this finding. Microscopic examination of the hair of the proposita shows abnormalities consisting of trichorrhexis nodosa, twisting of the hairshafts, and irregularity of the diameter of the hair, as was described recently in a patient with KS. This could be another occasional finding in this syndrome, but further studies are required. The presence of abnormal hair, nails, and the commonly described tooth abnormalities in KS further suggest ectodermal involvement in this syndrome.

Cutaneous porphyria in a neonate with tyrosinaemia type 1

A term infant born to consanguineous parents presented at birth with hypoglycaemia, thrombocytopenia, coagulopathy and hyperbilirubinaemia associated with polycythaemia due to delayed cord clamping. Despite phototherapy and correction of polycythaemia by partial exchange transfusion, coagulopathy, hypoglycaemia and conjugated hyperbilirubinaemia persisted, suggesting hepatic failure. Metabolic work-up led to the diagnosis of tyrosinaemia type 1 on day 4. Two--(2-nitro-4-trifluoromethylbenzoyl)--1,3 cyclohexanedione (NTBC) treatment, started on day 5, resulted in progressive clinical improvement and unambiguous biochemical response. Severe skin purpuric lesions occurred in areas exposed to phototherapy. These resolved slowly after its discontinuation. Urine analysis sampled just before and 6 days after starting NTBC treatment showed high levels of type 1 coproporphyrin isomers. Such findings do not seem directly related to tyrosinaemia type 1 where succinylacetone inhibits delta-aminolevulinic acid (delta-ALA) dehydratase and where the accumulation of delta-ALA results in neurotoxicity without photosensitivity.

CONCLUSION

We describe a cutaneous form of porphyria in a neonate presenting with severe liver failure due to tyrosinaemia type 1. This porphyria is tentatively attributed to a secondary accumulation of coproporphyrins due to cholestasis, as reported in the bronze baby syndrome and recently described in neonates with purpuric phototherapy-induced eruption, rather than to a primary defect of porphyrin metabolism. The hypothesis of a direct effect of tyrosinaemia type 1 on porphyrin excretion is also discussed.

Unilateral bowing of long bones and multiple congenital anomalies in a child born to a mother with gestational diabetes

We report on a new-born girl with multiple congenital anomalies consisting of major skeletal anomalies restricted to the left side, cleft palate, ventricular and atrial septal defect, retromicrognathia, short neck, dysplastic low-set ears and large birth weight. The left-side bony anomalies include shortening and bowing of the femur and tibia, hypoplasia of the fibula, hip dislocation, clubfoot and mild shortening of the long tubular bones in the left arm with elbow dislocation. The pregnancy was complicated by insulin-dependent gestational diabetes mellitus in the mother. The radiographic features were not consistent with the diagnosis of campomelic dysplasia, kyphomelic dysplasia or other skeletal dysplasias characterized by bowing and shortening of the long bones. To our knowledge, the multiple congenital anomalies, including major skeletal malformations, present in our case have never been simultaneously reported until now. A maternal diabetes syndrome in this infant is probable. The occurrence of major congenital malformations in offspring of women with gestational diabetes is reviewed and discussed. We provide evidence that gestational diabetes mellitus could be teratogenic. We recommend a careful diabetic control in every woman with a history of gestational diabetes.

Delineation of two distinct 6p deletion syndromes

Deletions of the short arm of chromosome 6 are relatively rare, the main features being developmental delay, craniofacial malformations, hypotonia, and defects of the heart and kidney, with hydrocephalus and eye abnormalities occurring in some instances. We present the molecular cytogenetic investigation of six cases with 6p deletions and two cases with unbalanced translocations resulting in monosomy of the distal part of 6p. The breakpoints of the deletions have been determined accurately by using 55 well-mapped probes and fluorescence in situ hybridization (FISH). The cases can be grouped into two distinct categories: interstitial deletions within the 6p22-p24 segment and terminal deletions within the 6p24-pter segment. Characteristics correlating with specific regions are: short neck, clinodactyly or syndactyly, brain, heart and kidney defects with deletions within 6p23-p24; and corneal opacities/iris coloboma/Rieger anomaly, hypertelorism and deafness with deletions of 6p25. The two cases with unbalanced translocations presented with a Larsen-like syndrome including some characteristics of the 6p deletion syndrome, which can be explained by the deletion of 6p25. Such investigation of cytogenetic abnormalities of 6p using FISH techniques and a defined set of probes will allow a direct comparison of reported cases and enable more accurate diagnosis as well as prognosis in patients with 6p deletions.

Noonan-like phenotype in monozygotic twins with a duplication-deficiency of the long arm of chromosome 18 resulting from a maternal paracentric inversion

We report on newborn monozygotic twins with a Noonan-like phenotype, and multiple congenital anomalies due to a monocentric recombinant chromosome 18. The mother carried a paracentric inversion of the long arm of chromosome 18, inv(18)(q21.1q22.3). Cytogenetic, fluorescent in situ hybridization, comparative genomic hybridization and DNA marker analyses allowed the delineation of the deleted (18q22.3-qter) and duplicated (18q12.1-q21.1) chromosomal regions in the recombinant chromosome 18, and suggest that this duplication-deletion chromosome 18 resulted from breakage of a dicentric recombinant chromosome 18 with subsequent reconstitution of telomeric sequences on the long arm. Marked variability is observed in the phenotypic expression of the same chromosomal anomaly in these monozygotic twins. The clinical findings of these patients are compared with those reported in proximal 18q-duplication and distal 18q-deletion patients. The clinical features of both infants are compatible with Noonan syndrome, suggesting that a locus for this syndrome may be located on the long arm of chromosome 18.

Alveolar soft-part sarcoma: further evidence by FISH for the involvement of chromosome band 17q25

A cytogenetic study of an alveolar soft-part sarcoma, a rare tumor of probably myogenic origin, demonstrated a t(X;17)(p11;q25) as the sole chromosomal abnormality. Dual- and triple-color fluorescence in situ hybridization, performed on metaphase and interphase cells, confirmed the translocation between chromosomes X and 17 and demonstrated that this translocation resulted in loss of 17q25. Involvement of 17q25 has been described in four previously published cases of alveolar soft-part sarcoma, but without further characterization. Compared to our karyotype, it seems that the derivative chromosome 17 observed in the reported cases could also be the result of a t(X;17) with possible loss of the 17q25 band. If so, a 17q25 deletion and/or chromosome rearrangement between Xp and 17q leading either to a gene fusion or gene disruption could play an important role in the pathogenesis of alveolar soft-part sarcoma.

Need for search for cryptic translocation in parents with several children affected with MCA: report of a cryptic translocation (10;14) detected by FISH

The 3 affected children from 2 different wedlocks of the mother have been previously described (11). Search by FISH analysis in the mother revealed she is a carrier of balanced translocation of clear terminal G bands of equal sizes of the long arms of chromosomes 10 and 14. Chromosomal slides of the last child (Patient 3) could be analysed by fish and revealed that he did inherit the derivative chromosome 10. He had a partial trisomy 14 and a partial deletion of the long arm of chromosome 10. The clinical pictures correspondence to the possibly abnormal karyotypes will be discussed.

Prenatal diagnosis of a constitutional interstitial deletion of chromosome 5 (q15q31.1) presenting with features of congenital contractural arachnodactyly

Prenatal diagnosis of a constitutional interstitial deletion of chromosome 5 (q15q31.1) in a 30-year-old woman is reported. At 21 weeks of pregnancy, routine fetal ultrasounds showed the presence of apparently isolated bilateral club feet. Fetal karyotyping documented an interstitial deletion of the long arm of chromosome 5: 46,XX,del(5) (q15q31) in all 50 analyzed metaphases. Because such deletion is associated with severe psychomotor retardation, the pregnancy was terminated. Postmortem karyotyping of skin fibroblasts confirmed the presence of this interstitial de novo deletion in all mitoses. The breakpoints on 5q were analyzed by fluorescent in situ hybridization and were localized at 5q15 and q31.1. This case illustrates the importance of fetal karyotyping in cases of isolated club feet. At autopsy, the fetus presented had minor anomalies and contractures of knee and hip joints. These clinical findings could fit the diagnosis of congenital contractural arachnodactyly (CCA) or Beals syndrome. CCA is caused by a defect in the fibrillin-2 (FBN2) gene. This gene was previously mapped on 5q23-31. Our molecular studies of both parents and the fetus, using an intragenic polymorphic GT repeat, showed that the FBN2 gene was deleted in the fetus and that the de novo interstitial deletion occurred on the paternally inherited chromosome 5. Thus, CCA may be caused by a loss of function of the FBN2 gene. Clinical findings in this fetus and those of other described cases with interstitial 5q deletions are reviewed, and similarities with CCA are stressed.

Growth failure, encephalopathy, and endocrine dysfunctions in two siblings, one with 5-oxoprolinase deficiency

Two female siblings, born to consanguineous parents, presented with a similar phenotype characterized by severe growth and developmental failure, dysmorphic features, thyroid and gonadal dysfunction, autistic traits and hand stereotypes resembling Rett syndrome. In the elder patient, analysis of urinary organic acids disclosed a very high excretion of 5-oxoproline (4.2 to 8.1 mol/mol creatinine) and enzyme assays of leucocyte extracts revealed a profound deficiency of 5-oxoprolinase. However, normal urinary organic acid profiles were found in the younger child. In view of their distinct dysmorphic features and severe growth deficiency, these siblings cannot be considered as Rett Syndrome variants. The Dubowitz and carbohydrate-deficient glycoprotein syndromes were also excluded clinically and biochemically respectively. We conclude that these patients suffer from a hitherto undescribed autosomal recessive disorder, unrelated to the 5-oxoprolinase deficiency of the elder sib.

CONCLUSION

The present findings give evidence that 5-oxoprolinase deficiency is not associated with a distinct morbid phenotype.

Feingold syndrome: report of a new family and review

Feingold syndrome (or oculodigitoesophagoduodenal syndrome; Microcephaly, Mesobrachyphalangy, Tracheo-esophageal fistula syndrome) is a dominantly inherited combination of hand and foot abnormalities, microcephaly, esophageal/duodenal atresia, short palpebral fissures and learning disabilities, first reported in 1975 (MIM 164280). We report on the seventh family with Feingold syndrome. The propositus is a male infant with esophageal and duodenal atresia, brachymesophalangy of the fifth fingers, bilateral syndactyly of toes 4-5 (and 2-3), relative microcephaly, and facial anomalies. His mother also has microcephaly, similar facial appearance, short fifth fingers with single flexion crease, syndactyly of toes 4-5, and learning disabilities. The maternal sister, brother, and grandmother of the propositus have the same phenotype. The 7 families with Feingold syndrome are reviewed. Intestinal (esophageal/duodenal) atresia/obstruction occurs in approximately 1/3 of the patients with Feingold syndrome.

Interstitial deletion 2q33.3-q34 in a boy with a phenotype resembling the Seckel syndrome

A boy presented at 5 weeks with a syndrome of pre- and postnatal growth retardation, microcephaly, muscular hypotonia, and facial anomalies resembling those seen in Seckel syndrome or microcephalic primordial dwarfism I. Analysis of prometaphase chromosomes, fluorescent in situ hybridization (FISH), and molecular studies showed the presence of a de novo chromosome 2 deletion that could be defined as del(2)(q33.3q34)pat. Parental chromosomes were normal, except for the presence of a paternal supernumerary marker identified by FISH as der(15). On follow-up of the patient during the next months length development appeared normal and the diagnosis of Seckel syndrome was withdrawn. Clinical findings of previously published cases with interstitial deletion of at least 2q33.3-q34, the deletion present in the propositus, are reviewed and include pre- and postnatal growth retardation, psychomotor retardation, microcephaly, micrognathia, and abnormal/low-set ears; findings also present in the propositus. These findings resemble those described in the Seckel syndrome. Noteworthy is the finding that 2/3 of the 60 reviewed cases originally reported as having Seckel syndrome apparently belong to a heterogeneous group of low birth weight microcephalic dwarfism I yet to be clearly defined. In these patients no chromosome 2q deletion has been reported so far. Retrospective analysis could show if a subgroup of these patients carry submicroscopic deletions at 2q33.3-q34. Alternatively, molecular analysis of this region may be warranted in newly diagnosed patients with Seckel syndrome-like manifestations.

A probable case of Wiedemann-Rautenstrauch syndrome or neonatal progeroid syndrome and review of the literature

A boy with features suggesting the diagnosis of Wiedemann-Rautenstrauch syndrome (WRS) or neonatal progeroid syndrome is presented. Abnormal findings included a generalized virtual absence of subcutaneous fat, sparse scalp hair, prominence of veins and muscles, a large and persistent anterior fontanelle and facial dysmorphism (triangular aged face, prominent eyes and scalp veins). Until now, only 13 cases (including one prenatal diagnosis) of this syndrome have been described. Since the borderlines of this syndrome are not very exact, we reviewed the previous reports in order to further delineate this rare syndrome.

Acrocallosal syndrome in an Algerian boy born to consanguineous parents: review of the literature and further delineation of the syndrome

We present a 17-month-old boy with the acrocallosal syndrome. He was born to consanguineous parents. Abnormal findings included agenesis of the corpus callosum, a ventricular septal defect (VSD), postaxial polydactyly of fingers, cleft soft palate, intestinal malrotation, large anterior fontanelle, prominent forehead, hypertelorism, epicanthic folds, short nose and mandible and preauricular skin tags, mixed hearing loss, laryngomalacia, and growth and severe motor and mental retardation. A review of previous reports on the acrocallosal syndrome shows considerable clinical variability; minimal diagnostic criteria are proposed. A developmental field defect with disturbance of midline development is suggested.

Prenatal diagnosis in Belgium

Prenatal diagnoses (PND) in Belgium are performed exclusively in licensed centres of medical genetics linked to university hospitals. These centres of genetics provide comprehensive genetic services which include, in addition to genetic tests, genetic counselling and moral support. These services are accessible to all residents in Belgium through coverage by the social security. PND has become a widely accepted procedure by the public and the health professionals, and has achieved significant prevention of birth defects, mainly chromosome abnormalities. The main problems involved in PND in Belgium are (1) the lack of regulations about indications for PND and (2) insufficient education in medical genetics in medical schools. It is hoped that the basic organisation of PND in Belgium will prevail in the future, with the proposed improvements.

New syndrome or severe expression of Gordon syndrome? A case report

A boy with multiple congenital anomalies including median cleft palate, bilateral hearing loss, clino- and camptodactyly, bilateral single palmar flexion creases, severe hypotonia with kyphoscoliosis and respiratory insufficiency, failure to thrive, bilateral cryptorchidism and facial dysmorphism (epicanthus, a flat nasal bridge, a small mouth, a small nose with anteverted nostrils, low-set ears, a prominent forehead, microretrognathia) is presented. His mother has a median cleft palate, bilateral hearing loss, single palmar flexion creases, and short stature. An autosomal or X-linked dominant syndrome with more severe expression in the proband than in his mother is suggested.

A detailed investigation of two cases exhibiting characteristics of the 6p deletion syndrome

Deletions of the short arm of chromosome 6 are relatively rare, only 16 cases having been described in the literature so far. Here we present a detailed investigation by fluorescence in situ hybridisation of two further cases with different but overlapping interstitial deletions involving 6p22, 6p23 and 6p24. The main features involved are craniofacial malformations, heart and kidney defects, mental retardation/developmental delay, hypotonia and hydrocephalus. By using 36 yeast artificial chromosome and cosmid clones from a contig covering 6p22.3-6p25 and other probes with defined cytogenetic locations within 6p21-6p22 we have precisely localised the breakpoints involved in each of the cases, estimated the sizes of the deleted regions and defined the region that is hemizygously deleted in both cases.

Clinical and cytogenetic studies of two cases of Klinefelter syndrome with hereditary retinoblastoma and rhabdomyosarcoma

Two children with Klinefelter syndrome (KS), one associated with bilateral hereditary retinoblastoma (RB) and the other with rhabdomyosarcoma (RMS) are reported. Both were boys and chromosomally mosaic for KS. The hereditary retinoblastoma case yielded 46,XY,del(13)(q12q14.2)/47, XXY(c),del(13)(q12q14.2) in PHA-stimulated lymphocytes. The rhabdomyosarcoma case yielded 46,XY/ 47,XXY(c) in peripheral blood cells whereas tumor revealed trisomy 8, trisomy 7, and t(7;13)(q33;q32) in addition to 46,XY/47,XXyc mosaicism.

[Leukemia lymphoma T-cell as first manifestation of ataxia-telangiectasia]

BACKGROUND

Variable degrees of T cell deficiency in ataxia-telangiectasia (AT) progressively worsen with time and death from malignant lymphoma is a common terminal event. T-cell lymphoma as the first manifestation of AT has never been reported.

CASE REPORT

A 22 month-old girl born to consanguineous parents, was treated for a thoracic T-cell lymphoma and remained in first complete remission, with a follow-up of 4 years. Prior to chemotherapy, cytogenetic studies on blood showed clonal rearrangements including t(7p;14q), T(2p;7q) and inv (7), while karyotype showed 6q- and 1p-mitoses on bone marrow blasts. Hypotonia became evident at 3 years. One year later, the neurological status deteriorated. The patient presented also severe respiratory tract infections. At that time, immunological investigations showed hypo IgG2, very low T4 lymphocytes level, all harbouring the CD45 RO phenotype. Increase in alpha-foetoprotein level, the ocular movements and the study of DNA synthesis after exposure to gamma-rays confirmed the diagnosis of AT.

CONCLUSION

In cases of childhood lymphoid neoplasia, AT should be considered whenever parental consanguinity, T-cell proliferation and/or unexpected toxic therapeutic responses are noted.

Hyperphosphatasemia in early diagnosed infantile GM1 gangliosidosis presenting as transient hydrops fetalis

The authors report a case of unsuspected fetal storage disorder initially diagnosed by placental examination performed because of a transient ascites at 28 weeks of gestation. At birth mild dysmorphic features and gradual neurological deterioration were observed. Highly elevated alkaline phosphatase levels were repeatedly noticed. Deficiency of beta-galactosidase was documented confirming GM1 gangliosidosis. Previous reports described the placental pathology after positive prenatal diagnoses of lysosomal diseases. In the present case, the postnatal diagnosis was made in view of the placental pathologic findings. Our observation indicates the need for thorough investigations in hydrops fetalis, in search for metabolic diseases.

Phosphaturia, glycosuria and aminoaciduria associated with idiopathic acquired sideroblastic anemia

Idiopathic acquired sideroblastic anemia is not a common disease. We studied the renal tubular function in such patients. Patients have lower calcium than controls (8.46 mg/dl +/- 0.59 vs 9.16 +/- 0.53). We have highlighted the multiple renal anomalies observed in patients with this type of hemopathy. The serum phosphate levels are lower in patients than in controls (2.73 +/- 0.36 vs 3.3 +/- 0.55 mg/dl, p = 0.0048). We found higher glycosuria (21:43 +/- 42.58 vs 0.0 +/- 0.0 mg/dl), total aminoaciduria (6280 +/- 3943 vs 4138 +/- 2269 microMol/g creatinine, p = 0.19) and lower maximum capacity for phosphate reabsorption by the renal tube (TmPO4) (2.11 +/- 0.38 vs 2.9 +/- 0.73 mg/100 ml GFR, p = 0.0027) in the patients. The association between idiopathic acquired sideroblastic anemia and the multiple tubular anomalies corresponding to the syndrome initially described by Fanconi has not been reported to date. The underlying mechanism is not understood, but, taken separately, these two anomalies commonly present heme metabolic anomalies in the mitochondria. We hypothesize that this syndrome could represent the clinical expression of a mitochondrial cytopathology.

Multiple clonal chromosome aberrations in a case of childhood focal nodular hyperplasia of the liver

A case of focal nodular hyperplasia is described that was accompanied by intense reactive stromal changes giving rise to a pseudosarcomatous appearance. Cytogenetic study revealed complex karyotypic abnormalities including five partially identifiable clonal aberrations and one marker chromosome. The composite karyotype was interpreted as: 45-46,XY,add(4)(q21-25)[24], add(11)(p14)[24], add (19)(p13)[15], der(20)t(1;20)(q25;p12)[31], add(21) (q22)[13],-22[3], +mar[2][cp31]. In addition, quadriradial or complex figures, telomeric associations tas, unidentified ring chromosomes, chromosome breaks, and markers were seen in some cells. Such cytogenetic findings, although suggestive of malignancy, could most likely be related to a nonneoplastic condition, i.e., the unusual florid reactive changes associated with this focal nodular hyperplasia.

Frequent deletion of chromosome 19 and a rare rearrangement of 19p13.3 involving the insulin receptor gene in human ovarian cancer

Human ovarian cancer cells usually have multiple specific chromosomal deletions which can be detected by cytogenetic analysis or molecular techniques. Tumour suppressor genes might be located in these deleted chromosomal segments. The importance of these different loci is usually estimated from the frequency with which they are deleted. Here we report a 59% loss of heterozygosity for chromosome 19 in the DNA of human invasive epithelial ovarian cancer from a series of 37 patients. In all cases informative on both chromosomal arms a subchromosomal loss is observed. Analysis of the same tumours for chromosome 17p and 11p loss suggests that loss of chromosome 19p/q is less important than 17p loss, but more important than 11p loss. The deletion of chromosome 19q seems to be associated with distant, hematogeneous metastasis (stage IV). In two patients with high grade tumours, the deletion involves a rearrangement of the insulin receptor locus (19p13.3). This suggests that some of the previously described frequent cytogenetic 19p+ markers and 19p13.3 breaks observed in high grade ovarian cancers, might actually occur in the insulin receptor gene.

Cordocentesis for rapid karyotype: 421 consecutive cases

Between October 1985 and December 1993, 421 patients underwent fetal blood sampling for rapid karyotyping (426 samplings, 5 twin pregnancies). The aim of the study was to evaluate cordocentesis in terms of results, complications and additional information in this specific indication especially in case of abnormal pregnancy sonogram. The fetal loss rate possibly related to fetal blood sampling was 1.9%. Abnormal sonograms represented 91% of rapid karyotype indications. Chromosomal abnormalities were found in 9.5% of abnormal sonograms and in 16.9% of fetal structural anomalies (37 cases). The commonest chromosomal abnormality was trisomy 21 (11 cases). In conclusion, cordocentesis is a safe and reliable method for rapid karyotyping although it is associated with more risks than in other indications (congenital infections). The high rate of chromosomal abnormalities pleaded for ultrasonographic screening in a population usually not investigated by cytogenetic studies.

Severe Smith-Lemli-Opitz syndrome with prolonged survival and lipid abnormalities

We have studied a girl with multiple congenital anomalies, growth and mental deficiency, characteristic facial anomalies, cataracts, cerebellar atrophy, and severe hypocholesterolemia. Death occurred at age 7 years. After excluding several syndromes, i.e., peroxisomal disorders, mevalonic acidaemia, and Marinesco-Sjögren syndrome, it is concluded that this girl had severe Smith-Lemli-Opitz Syndrome (SLOS) with exceptionally long survival. This diagnosis was confirmed through assay of 7-dehydrocholesterol in cultured fibroblasts.

Isodisomy of chromosome 6 in a newborn with methylmalonic acidemia and agenesis of pancreatic beta cells causing diabetes mellitus

Isodisomy (ID) is a genetic anomaly defined as the inheritance of two copies of the same genetic material from one parent. ID in an offspring is a rare cause of recessive genetic diseases via inheritance of two copies of a mutated gene from one carrier parent. We studied a newborn female with a mut(o) of methylmalonic acidemia and complete absence of insulin-producing beta cells in otherwise normal-appearing pancreatic islets, causing insulin-dependent diabetes mellitus. The patient died 2 wk after birth. Serotyping of the HLA antigens, DNA typing of HLA-B and HLA class II loci, study of polymorphic DNA markers of chromosome 6, and cytogenetic analysis demonstrated paternal ID, involving at least a 25-centiMorgan portion of the chromosome pair that encompasses the MHC. ID probably caused methylmalonic acidemia by duplication of a mutated allele of the corresponding gene on the chromosome 6 inherited from the father. It is also very likely that ID was etiologically related to the agenesis of beta cells and consequent insulin-dependent diabetes mellitus in our patient. We thus speculate on the existence of a gene on chromosome 6 involved in beta cell differentiation.

Granulocytic sarcoma showing chromosomal changes other than the t(8;21)

Cytogenetic analysis of a granulocytic sarcoma showed a 46,XX,der(X)t(X;1) (q28;q22), inv(3)(p21q27), inv(9)(p13q22),t(12;22)(p11;q11) karyotype. In addition, bone marrow aspirate disclosed the presence of cells with a 46,XX,inv(3)(p21q27),inv(9)(p13q22)(p11;q11) chromosomal pattern while the patient was clinically aleukemic. This case demonstrates that chromosomal abnormalities other than the classical t(8;21) can also be associated with granulocytic sarcoma.

Anaplastic large cell lymphoma of true histiocytic origin in an infant: unusual clinical, hematological, and cytogenetic features

We report here the case of a 7-month-old boy who developed anaplastic large cell lymphoma of true histiocytic origin or malignant histiocytosis, with fever, bone and bone marrow infiltration. Usual clinical features were absent. The neoplastic nature of the disease was supported by the presence of clonal chromosomal abnormalities [t(6;8)(p23;p21),der(8)del(8)(q11aq13), der(22) t(11;22) (q13;13)]. Neither B nor T lineage could be demonstrated here. Morphology, ultrastructural analysis, surface antigens expression, and cytogenetics were more specific for the monocyte-macrophage lineage.

[Fetal cardiology: prenatal diagnosis of cardiac malformations]

Foetal cardiology is now a recognised chapter of both paediatric cardiology and foetal medicine. We describe here our experience with antenatal diagnosis of cardiac malformations and discuss both its genetic and epidemiological issues. Our experience confirms if need be that foetal medicine requires a well organised first-level foetal evaluation.

Chromosomal findings in cultured melanocytes from a giant congenital nevus

A giant congenital pigmented nevus was observed in a newborn male. A melanocyte culture was established from nevus fragments removed at age 6 days. Analysis of 136 metaphases harvested from the primary culture showed 74% normal mitoses, 22% polyploids, and 4% mitoses with chromosome rearrangements involving in particular 1p, 12q, and 19p. In addition, the culture showed a high level of HLA-DR expression. Although histology showed no sign of malignancy, these findings may illustrate one of the first events which might eventually progress toward malignancy.

Pyruvate dehydrogenase deficiency: clinical and biochemical diagnosis

A female neonate with pyruvate dehydrogenase (PDH) deficiency is presented with clinical, radiologic, biochemical, neuropathologic, and molecular genetic data. She was dysmorphic, with a high forehead, lowset ears, thin upper lip, upturned nose, and rhizomelic limbs. Cranial MRI revealed severe cortical atrophy, ventricular dilatation, and corpus callosum agenesis. Pyruvate and lactate levels were increased in CSF and blood. Urinary organic acid profile was compatible with PDH deficiency. PDH activity was normal in fibroblasts, lymphocytes, and muscle. The PDH E1-alpha gene was sequenced and a single base mutation was found within the regulatory phosphorylation site in exon 10. It is postulated that this mutation causes a cerebral form of PDH deficiency. Tissue-specific expression of the disease could be explained by differential X chromosome inactivation because the PDH E1-alpha gene is located on this chromosome. Dysmorphism with severe cerebral malformations in female patients merits a metabolic evaluation, including determination of lactate and pyruvate levels in CSF.

Congenital absence of insulin cells in a neonate with diabetes mellitus and mutase-deficient methylmalonic acidaemia

We report on a female neonate with diabetes mellitus and methylmalonic acidaemia, who died at age 16 days. Using immunocytochemistry, electron microscopy and in situ hybridisation, we were unable to demonstrate any insulin cells in the pancreatic islets. Methylmalonic acidaemia was caused by a methylmalonyl coenzyme A mutase apoenzyme defect. The metabolic crisis of the methylmalonic acidaemia aggravated the diabetes and may explain the failure of insulin therapy. Our results suggest that the infant suffered from a congenital absence of beta cells associated with a genetically transmitted mutase apoenzyme defect.