Biochemical and molecular analyses in three patients with 3-hydroxy-3-methylglutaric aciduria

Two methods, spectrophotometry and HPLC, were compared in the analyses of 3-hydroxy-3-methylglutaryl-CoA lyase (HL) activity in three unrelated Czech patients with 3-hydroxy-3-methylglutaric (HMG) aciduria and their family members. The HL activities in cultured fibroblasts and/or isolated lymphocytes of probands were below the detection limits of the methods used. Both methods were also suitable for recognition of all heterozygotes in affected families. We searched for pathogenic mutations in the HL gene. Molecular analyses revealed that two patients are homozygous for known mutation H233R and R41Q, respectively, whereas the third patient is a compound heterozygote for the mutation H233R and a novel mutation Pro9fs(−1). This study expands the knowledge of the genotypic variability of the HMG aciduria. This revised version was published online in September 2006 with corrections to the Cover Date.     

Differential HMG-CoA lyase expression in human tissues provides clues about 3-hydroxy-3-methylglutaric aciduria

3-Hydroxy-3-methylglutaric aciduria is a rare human autosomal recessive disorder caused by deficiency of 3-hydroxy-3-methylglutaryl CoA lyase (HL). This mitochondrial enzyme catalyzes the common final step of leucine degradation and ketogenesis. Acute symptoms include vomiting, seizures and lethargy, accompanied by metabolic acidosis and hypoketotic hypoglycaemia. Such organs as the liver, brain, pancreas, and heart can also be involved. However, the pathophysiology of this disease is only partially understood. We measured mRNA levels, protein expression and enzyme activity of human HMG-CoA lyase from liver, kidney, pancreas, testis, heart, skeletal muscle, and brain. Surprisingly, the pancreas is, after the liver, the tissue with most HL activity. However, in heart and adult brain, HL activity was not detected in the mitochondrial fraction. These findings contribute to our understanding of the enzyme function and the consequences of its deficiency and suggest the need for assessment of pancreatic damage in these patients.     

Pregnancy in women with congenital factor VII deficiency

The aim was to review the pregnancy and obstetric outcome in women with factor VII (FVII) deficiency. The study group contained women with FVII deficiency, registered with Haemophilia centre and Haemostasis Unit at the Royal Free Hospital, London. The women were interviewed and case notes were reviewed. The main outcome measures were changes in FVII levels in pregnancy, maternal and perinatal outcome. The FVII levels ranged from 7-36 IU dL(-1) in the 13 women included in the study. There were a total of 14 pregnancies in seven women. Ten pregnancies in four women were prior to the diagnosis of FVII deficiency. Following the diagnosis of FVII deficiency, there were four pregnancies in three women. There was an increase in the FVII level during pregnancy in these women from a mean baseline level of 33 IU dL(-1) to a mean of 73 IU dL(-1). These women received recombinant FVIIa replacement during labour and delivery. There were two early pregnancy losses, both associated with excessive haemorrhage. There was only one postpartum haemorrhage in the study. There is a significant increase in FVII levels in pregnancy in women with heterozygous FVII deficiency. The risk of bleeding in early pregnancy might be higher than that at term, due to inadequate rise in the FVII level in early pregnancy.     

Pregnancy issues in inherited metabolic disorders

Summary Increasing numbers of individuals with inherited metabolic disorders are surviving into adulthood and considering their reproductive options. This paper discusses a practical approach to supporting such individuals, focusing on issues concerning fertility, the impact of pregnancy on metabolism and the metabolic disorder itself on the pregnancy, as well as highlighting the need to pay special attention during the postpartum period. Apart from pregnancies in women with phenylketonuria, there is a dearth of data in this area and a great need for collection of information within registries to aid our understanding of potential problems and counselling of women and their partners. Presented at the 42nd Annual Meeting of the SSIEM, Paris, 6–9 September 2005 Competing interests: None declared     

3-Hydroxy-3-methylglutaric aciduria: Response to carnitine therapy and fat and leucine restriction

A female infant, born to first cousin parents, lapsed into coma with severe metabolic acidosis on day three of life. The gas chromatographic/mass spectrometric urinary organic acid profile showed marked elevation of the leucine metabolites 3-hydroxy-3-methylglutaric, 3-methylglutaconic, 3-methylglutaric and 3-hydroxy-isovaleric acids. Less than 5% of the normal activity of the enzyme 3-hydroxy-3-methylglutaryl CoA lyase was detected in cultured skin fibroblasts. The patient's total and free carnitine was initially low but rose to normal levels after placing her ondl-carnitine (100 mg kg^–1 d^–1). On a diet providing 87 mg kg^–1 d^–1 of leucine and only 25% of total calories as fat and 2 g kg^–1 d^–1 protein, the concentration of the urinary organic acids fell markedly. She is now 15 months old with normal growth and development. This regimen appears effective in the early treatment of 3-hydroxy-3-methylglutaric aciduria.     

Multifactorial thrombophilia in a pregnancy: a case report.

Thrombophilias are inherited or acquired conditions that predispose individuals to thromboembolism. Thrombophilic disorders increase obstetric complications, such as early pregnancy loss, fetal growth retardation, placental abruption, and preeclampsia. Recurrent pregnancy loss affects 1% to 3% of women of reproductive age, and a large proportion of these losses remain unexplained. Thrombophilic defects were found in 49% to 65% of women with pregnancy complications compared with 18% to 22% of women with normal pregnancies, suggesting a 3- to 8-fold increase in risk. We report a case of a pregnant woman who had a history of recurrent pregnancy losses that was complicated with protein S deficiency, factor V Leiden mutation, methylene tetrahydrofolate reductase mutation, and antiphospholipid syndrome in her pregnancy.     

Bloodspot acylcarnitine and amino acid analysis in cord blood samples: efficacy and reference data from a large cohort study

Summary Background:  In order to test the feasibility of cord blood screening for inherited metabolic disease, a two-year cohort study of births in six obstetric units from five towns in the north of England was undertaken. These towns have a high prevalence of consanguineous marriages, largely among the immigrant Asian community. The purpose of the study was to determine whether early detection of metabolic disease was possible and whether early intervention would improve prognosis. Methods:  Following parental consent, cord blood samples were collected at birth and analysed for acylcarnitine and amino acid profiles by tandem mass spectrometry in one of two laboratories. One laboratory used butylated derivatives, the other used underivatized samples. The same laboratories performed routine blood spot neonatal screening at 5–7 days of age on these babies. Patients with positive results were investigated and treated by a metabolic paediatrician as soon as possible. Results:  24 983 births were examined. 12 952 samples were analysed as butyl derivatives, 12 031 samples were analysed underivatized. The following disorders were detected: medium-chain acyl-CoA dehydrogenase (MCAD) deficiency (1 case), 3-methylcrotonyl-CoA carboxylase (MCC) deficiency (2 cases), maternal carnitine transporter defect (2 cases), maternal MCC (1 case). The following disorders were diagnosed subsequently but were not detected by the cord blood screening: phenylketonuria (PKU) (1 case), maple syrup urine disease (MSUD) (2 cases), argininosuccinic aciduria (1 case), methylmalonic acidaemia (MMA) (1 case), glutaric aciduria type 2 (1 case), MCAD deficiency (2 cases), 3-hydroxy-3-methylglutaryl-CoA lyase deficiency (1 case). Comprehensive reference data for all analytes by both methods were obtained. Conclusions:  Cord blood testing is of limited value in detecting inherited metabolic disease. The metabolites associated with most disorders examined were not elevated in cord blood. Some maternal disorders, carnitine transporter defect and 3-methlycrotonyl-CoA carboxylase deficiency, are detected. These remain of uncertain clinical significance. Comprehensive reference data have been obtained that will facilitate future interpretation of studies in cord blood. Competing interests: None declared     

Changes in antithrombin activity and platelet counts in the late stage of twin and triplet pregnancies

It is possible that women with triplet pregnancies are more likely to exhibit pregnancy-induced antithrombin deficiency, gestational thrombocytopenia, and perinatal elevation in serum aspartate aminotransferase (AST) than women with twin pregnancies. We retrospectively reviewed changes in antithrombin activity, platelet count, and blood chemistry in 23 twin and seven triplet pregnancies in which the mothers received antenatal care and gave birth in our hospital during 1999 and 2001. Both antithrombin activity and platelet counts gradually decreased until delivery, then promptly increased after delivery in both twin and triplet pregnancies. A significantly larger number of women developed gestational thrombocytopenia of < 100 x 10 (9)/L (43% [three of seven] versus 4.3% [one of 23]; p < 0.01) and pregnancy-induced antithrombin deficiency of < 60% of normal activity (57% [four of seven] versus 17% [four of 23]; p < 0.05) in triplet than in twin pregnancies. Eight women with pregnancy-induced antithrombin deficiency, including three women with gestational thrombocytopenia, were significantly more likely to develop perinatal elevations of AST, lactate dehydrogenase, serum creatinine, fibrin/fibrinogen degradation products, and D-dimer than were those without pregnancy-induced antithrombin deficiency. These findings suggest that women with triplet pregnancies are at an increased risk of the HELLP syndrome and acute fatty liver of pregnancy compared with women with twin pregnancies.     

Perinatal aspects of inherited thrombophilia

The identified main causes of inherited thrombophilia are deficiencies of antithrombin, protein C and protein S, activated protein C (APC) resistance and the factor V Leiden mutation, mutant factor II, and inherited hyperhomocysteinemia. In women from symptomatic families these defects may be associated with an increased risk of venous thrombosis in pregnancy and recurrent fetal loss. Inherited thrombophilia is common and appears to be a multigene disorder. The thrombotic risk would seem to be greatest in women with antithrombin deficiency and more than one thrombophilia defect. The abnormalities that are now recognized represent only part of the genetic predisposition to thrombosis. In assessing thrombotic risk in pregnancy, acquired risk factors as well as genetic predisposition should be considered. Increasing age, obesity, immobility, and delivery by cesarean section are major risk factors. Pregnancy should be planned, and each patient should be managed on an individual basis. In pregnancy, heparin is the anticoagulant of choice, and as far as possible, treatment with warfarin should be avoided because of the risks to the fetus. When patients are on long-term treatment with warfarin, pregnancy should be avoided, and warfarin should be discontinued prior to embarking on a pregnancy or as soon as pregnancy is suspected and before 6 weeks' gestation. In women from symptomatic families with antithrombin deficiency, adjusted dose heparin throughout pregnancy is recommended and warfarin for at least 3 months post partum. In protein C and protein S deficiency, factor V Leiden, or mutant factor II, treatment can be based on personal and family history. Thromboprophylaxis in late pregnancy and post partum should be considered. Fetal loss may be increased in women with inherited thrombophilia. The risk appears greatest in women with antithrombin deficiency and women with more than one thrombophilia defect. A number of reports have claimed that prophylactic treatment with heparin during pregnancy has resulted in successful pregnancy in women with recurrent fetal death and inherited thrombophilia.     

Crohn's disease as a risk factor for the outcome of pregnancy

BACKGROUND/AIMS: To study the effects of Crohn's disease on the course of pregnancy and the influence of pregnancy on the activity of Crohn's disease. METHODOLOGY: The course of 35 pregnancies in 23 women with Crohn's disease were reviewed over a 12 years period. RESULTS: Nine pregnancies (25%) started when Crohn's disease was active. We observed 2 exacerbations among the 9 pregnancies with active disease and 7 exacerbations among the 26 pregnancies with quiescent disease: this represents a total exacerbation rate of 26% similar to non-pregnant women with Crohn's disease. The course of pregnancy was normal with a full-term delivery in 22 cases (63%). We observed 5 premature deliveries (14%), 5 spontaneous abortions (14%), 1 induced abortion (3%) and 2 liveborns with severe malformations (6%). Preterm delivery was significantly associated with reactivation of Crohn's disease during pregnancy (P = 0.009), whereas fetal loss was significantly associated with activity of Crohn's disease at the time of conception (P = 0.015). CONCLUSIONS: Pregnancy does not appear to influence the course of Crohn's disease. The relapse rate of Crohn's disease during pregnancy is similar to that of the general Crohn's disease population. Active Crohn's disease at the time of conception or reactivation during pregnancy are risk factors for abnormal pregnancy outcome.     

Severe factor X deficiency in pregnancy: case report and review of the literature

Isolate factor X deficiency is an extremely rare clotting factor disorder inherited in autosomal recessive fashion and pregnancy in a homozygous patient is frequently complicated by recurrent miscarriage, uterine bleeding and premature labour. Eleven pregnancies in seven patients affected by FX deficiency have been reported in the literature. Two additional pregnancies have been reported in a FX variant (FX Friuli). We present a new case of successful at term pregnancy in a homozygous patient.     

3-Hydroxy-3-methylglutaryl-coenzyme A lyase deficiency: A review

Children with 3-hydroxy-3-methylglutaryl-CoA lyase deficiency (HMG-CoA-LD; McKusick 24645), have inherited two areas of metabolic weakness. Firstly, they are unable to metabolize fully the carbon skeleton of leucine, and secondly, they cannot make ketone bodies in response to prolonged fasting. In the first year of life infants with HMG-CoA-LD run a high risk of developing severe hypoglycaemia which can lead to death if prompt intervention does not occur. The metabolic crisis develops when the infant is first introduced to dietary protein soon after birth, or later, when a reduced intake of glucose, often during a viral infection, results in a drain on the infant's circulating glucose levels. However, where diets are adequately adjusted to limit protein and fat intake, the metabolic handicaps of individuals with HMG-CoA-LD are not exposed and they are virtually symptomless. As children with HMG-CoA-LD grow older the incidence of hypoglycaemic attacks diminishes and they usually develop normally. This article reviews literature on cases of HMG-CoA-LD and interprets data on altered metabolism in these children.     

Pregnancy outcome in congenital dyserythropoietic anemia type I

Objectives: Congenital dyserythropoietic anemia type I (CDA I) is a rare inherited disease characterized by moderate to severe macrocytic anemia and abnormal erythroid precursors with nuclear chromatin bridges and spongy heterochromatin. Moderate to severe maternal anemia is a recognized independent risk factor for low birth weight (LBW) and complicated delivery. The aim of the study was to review the outcome of pregnancies in women with CDA I. Methods: The clinical and laboratory records of 28 spontaneous pregnancies in six Bedouin women with CDA I were reviewed. The results were compared with findings from a retrospective review of a large population‐based registry including all pregnancies in Bedouin women during the same 15‐yr period. Results: Eighteen pregnancies in women with CDA I (64%) were complicated. One pregnancy was aborted spontaneously in the first trimester and one resulted in a non‐viable fetus (stillborn at 26 wk). Cesarean section (CS) was performed in 10 pregnancies (36%). Eleven of the 26 newborns (42%) had a LBW: six were born prematurely and five were small for gestational age. The odds ratio for CS in women with CDA I compared with healthy Bedouin women was 4.5 [95% confidence interval (CI) 1.2–10.3], and for a LBW infant, 5.5 (95% CI 2.4–12.3). Careful follow‐up was associated with significantly better fetal outcome (P = 0.05). Conclusions: Pregnancies in women with CDA I are at high risk for delivery‐related and outcome complications. To improve fetal outcome, women with CDA I should be carefully monitored during pregnancy.     

Pregnancy and its management in women with GSD type III - a single centre experience

We present a review of our experience and pregnancy outcome in patients with GSD III managed by our centre. Between 1997 and 2010 there were 15 pregnancies in seven women with GSD III. Four women had GSD IIIb (nine pregnancies) and three GSD IIIa (six pregnancies). There was a successful outcome in all 15 pregnancies with delivery of 15 liveborn infants. Four infants were of low birthweight (<2nd centile) but all have developed normally apart from one with behavioural/psychiatric problems. Three women had pre-existing cardiomyopathy prior to pregnancy. One of these women had deterioration of her cardiomyopathy during pregnancy and again in the post-partum period. Women with GSD III do not seem to have any issues with fertility. Overall the outcome of pregnancy for both mother and child is good. Care needs to be taken to avoid maternal hypoglycemia which may be associated with intrauterine growth restriction and low birth weight. Cardiac function should be monitored carefully particularly in those with pre-existing cardiomyopathy.     

Anticoagulation in pregnant women with mechanical heart valve prostheses

OBJECTIVE: To evaluate the outcome of pregnancy in women with mechanical heart valve prostheses in relation to the anticoagulant treatment used in the first trimester and the incidence of thrombotic and bleeding complications. METHODS: 92 pregnancies in 59 women were followed between 1986 and 1997. In 31 pregnancies, oral anticoagulants were discontinued when pregnancy was diagnosed and subcutaneous heparin was started (12 500 U every 12 hours) adjusted to prolong the adjusted partial thromboplastin time to twice the control level. In the second trimester oral anticoagulants were resumed but changed to heparin again 15 days before the expected delivery date. In 61 pregnancies oral anticoagulants were continued during the first trimester. The same regimen of heparin was used for delivery. RESULTS: Abortion or fetal losses were similar (p = 0. 5717) in women exposed to oral anticoagulants in the first trimester (13/61; 25%) compared with those who received adjusted subcutaneous heparin (6/31; 19%). Embolic episodes were more common (p = 0.0029) in women who received heparin (4.92%) compared with those on oral anticoagulants (0.33%). Embolic episodes were cerebral and transient. No valve thromboses were observed. No malformations appeared in the 71 newborns, except for one case of hydrocephalus. There were no maternal deaths secondary to thrombotic complications. The only death was the result of major bleeding after the delivery of a premature stillborn. CONCLUSIONS: Oral anticoagulants seem to be safer for the mother than adjusted subcutaneous heparin. Heparin does not offer a clear advantage over oral anticoagulation in the pregnancy outcome.     

A retrospective 11-year analysis of obstetric patients with idiopathic thrombocytopenic purpura

Numerous studies have examined the outcomes of infants born to mothers with idiopathic thrombocytopenic purpura (ITP). Fewer studies have discussed the morbidity of obstetric patients with ITP. We describe a retrospective study of 92 women with ITP during 119 pregnancies over an 11-year period. Most women had thrombocytopenia during pregnancy. At delivery, women in 98 pregnancies (89%) had platelet counts lower than 150 x 109/L; most had mild to moderate thrombocytopenia. For many, the pregnancy was uneventful; however, women had moderate to severe bleeding in 25 pregnancies (21.5%). Women in 37 pregnancies (31.1%) required treatment to increase platelet counts. During delivery, 44 women (37.3%) received epidural analgesia without complications, with most having a platelet count between 50 and 149 x 109/L. Most deliveries (82.4%) were vaginal. Bleeding was uncommon at delivery. Infant platelet counts at birth ranged from 12 to 436 x 109/L; 25.2% of infants had platelet counts lower than 150 x 109/L, and 9% had platelet counts lower than 50 x 109/L. Eighteen infants (14.6%) required treatment for hemostatic impairment. Two fetal deaths occurred. One was caused by hemorrhage. ITP in pregnancy carries a low risk, but mothers and infants may require therapy to raise their platelet counts.     

Pregnancy and rare bleeding disorders

Summary.  Rare bleeding disorders include deficiency of fibrinogen, prothrombin, factor V, factor VII, factor X, factor XI and factor XIII together with combined deficiency disorders, factor V+VIII deficiency, and deficiency of the vitamin K-dependent factors (factor II, VII, IX and X). They account for 3–5% of all inherited coagulation disorders. Due to their rarity, information about pregnancy complications and management is limited and mostly derived from case reports. Deficiency of fibrinogen and FXIII are both found to be strongly associated with increased risk of recurrent miscarriage and placental abruption. Factor replacement is used to reduce these risks. However, the risk of miscarriage and ante-partum complications is less clear in women with other bleeding disorders. Haemostatic abnormalities in women with rare bleeding disorders seem to persist throughout pregnancy especially if the defect is severe. Therefore women affected with these disorders are at risk of post-partum haemorrhage. The fetus can also be affected and potentially at risk of bleeding complications. Specialised multidisciplinary management is essential to minimise the potential maternal and neonatal complications and ensure an optimal outcome. This paper presents literature review for pregnancy complications in each of the rare bleeding disorders. In addition general principles for management of pregnancy, labour and delivery are discussed.     

Pregnancies and Oral Contraceptive Therapy in Severe (Homozygons) FXII Deficiency: A Study in 12 Patients and Review of the Literature

Twelve women with severe Factor XII (FXII) deficiency were under observation for an average period of about 16 years. During this time, these women had 19 pregnancies without any bleeding or thrombotic complications. The evaluation of the literature has shown that three patients manifested deep vein thrombosis during pregnancy. Five women also showed mild bleeding at delivery .The significance of these findings is not clear since thrombotic and bleeding complications may occur occasionally even in normal women. Five of our patients took oral contraceptive therapy during their fertile life for a variable period of time (2–10 years). No thrombosis was noted in any of these patients. From the scanty data gathered, in this respect, from the literature, it was shown that only three women with severe FXII deficiency took oral contraceptives and no thrombosis was noted. Altogether these results seem to indicate that the FXII deficiency does not play any significant role in the pathogenesis of bleeding and of thrombotic complications in pregnancy. However, the occurrence of deep vein thrombosis in 3 out of the 64 patients for whom sufficient data could be gathered indicates the need for further studies. This is more so if one considers that 3 out of the 6 cases of venous thromboses described altogether in the literature for females with severe FXII deficiency occurred during pregnancy or puerperium.This revised version was published online in May 2005 with a corrected cover date.