Alport syndrome and pregnancy: Good obstetric and nephrological outcomes in a pregnant woman with homozygous autosomal recessive Alport syndrome

Reassuring pregnancy outcomes in women with mild COL4A3-5-related disease (Alport syndrome) and genetic type of disease can aid personalized counseling

Individualized pre-pregnancy counseling and antenatal care for women with chronic kidney disease (CKD) require disease-specific data. Here, we investigated pregnancy outcomes and long-term kidney function in women with COL4A3-5 related disease (Alport Syndrome, (AS)) in a large multicenter cohort. The ALPART-network (mAternaL and fetal PregnAncy outcomes of women with AlpoRT syndrome), an international collaboration of 17 centers, retrospectively investigated COL4A3-5 related disease pregnancies after the 20th week. Outcomes were stratified per inheritance pattern (X-Linked AS (XLAS)), Autosomal Dominant AS (ADAS), or Autosomal Recessive AS (ARAS)). The influence of pregnancy on estimated glomerular filtration rate (eGFR)-slope was assessed in 192 pregnancies encompassing 116 women (121 with XLAS, 47 with ADAS, and 12 with ARAS). Median eGFR pre-pregnancy was over 90ml/min/1.73m2. Neonatal outcomes were favorable: 100% live births, median gestational age 39.0 weeks and mean birth weight 3135 grams. Gestational hypertension occurred during 23% of pregnancies (reference: 'general' CKD G1-G2 pregnancies incidence is 4-20%) and preeclampsia in 20%. The mean eGFR declined after pregnancy but remained within normal range (over 90ml/min/1.73m2). Pregnancy did not significantly affect eGFR-slope (pre-pregnancy β=-1.030, post-pregnancy β=-1.349). ARAS-pregnancies demonstrated less favorable outcomes (early preterm birth incidence 3/11 (27%)). ARAS was a significant independent predictor for lower birth weight and shorter duration of pregnancy, next to the classic predictors (pre-pregnancy kidney function, proteinuria, and chronic hypertension) though missing proteinuria values and the small ARAS-sample hindered analysis. This is the largest study to date on AS and pregnancy with reassuring results for mild AS, though inheritance patterns could be considered in counseling next to classic risk factors. Thus, our findings support personalized reproductive care and highlight the importance of investigating kidney disease-specific pregnancy outcomes.

Good maternal and fetal outcomes of three consecutive pregnancies in a Mediterranean woman with Alport syndrome: a case report

BACKGROUND

Alport syndrome is a rare inherited disorder affecting the glomerular basement membrane, manifested by hematuria and proteinuria that is commonly associated with ocular and hearing defects. There is limited information about the maternal and fetal outcomes of Alport syndrome in pregnancy.

CASE PRESENTATION

We describe a smooth course of pregnancy, a good maternal outcome, and a good fetal outcome in three consecutive pregnancies for a 35-year-old Mediterranean woman with Alport syndrome over a 10-year duration. Although there was a nephrotic range of progressive proteinuria in all her pregnancies, there was a prompt drop in proteinuria within 2 weeks of her deliveries. She has constantly shown a normal serum creatinine level and a normal serum protein level in all her pregnancies. Apart from a single episode of asymptomatic hypertension in her second pregnancy at 34 weeks of gestation that returned to a normal range immediately after delivery, she was normotensive antenatally and postnatally. She gave birth by cesarean section to three healthy newborns.

CONCLUSIONS

A normal prepregnancy creatinine level and a mild range of proteinuria in a patient with normotension, who is not on any medication, are associated with good maternal and fetal outcomes. Furthermore, successful pregnancy that is followed by a normal renal function test might suggest a favorable outcome for any future pregnancy.

Slowly Progressive Male Alport Syndrome Evaluated by Serial Biopsy: Importance of Type IV Collagen Staining

A slowly progressive middle-aged man initially diagnosed with thin basement membrane nephropathy based on extensive thinning of the glomerular basement membrane (GBM) was subsequently diagnosed with Alport syndrome (AS) by a serial renal biopsy eight years later. The ultrastructural analysis of the second biopsy indicated thickening and wrinkling with mild reticulation in the GBM, consistent with AS. However, a retrospective analysis of the first biopsy revealed mild attenuation of type IV collagen α5 chain staining, suggesting a potential diagnosis of AS, despite the lack of ultrastructural features of AS. We herein report the clinical usefulness of type IV collagen staining in the early diagnosis of AS.

Preimplantation Genetic Testing Prevented Intergenerational Transmission of X-Linked Alport Syndrome

BACKGROUND

Alport syndrome (AS) is a hereditary renal basement membrane disease that can lead to end-stage renal disease in young adults. It can be diagnosed by genetic analysis, being mostly caused by mutations in COL4A3, COL-4A4, and COL4A5. To date, there is no radical cure for this disease.

OBJECTIVES

The aim of this study was to avoid the transmission of AS within an affected family by selecting healthy embryos for uterine transfer. The embryos were identified by preimplantation genetic testing for monogenic disorders (PGT-M).

METHODS

We used next-generation sequencing (NGS) to identify mutations in the proband and his parents. The results of NGS were confirmed by Sanger sequencing. Targeted NGS combined with targeted single-nucleotide polymorphism haplotyping was used for the in vitro identification of COL4A5 mutations in human embryos to prevent their intergenerational transmission.

RESULTS

The c.349_359delGGACCTCAAGG and c.360_361insTGC mutations in COL4A5 were identified in a family affected by X-linked AS. Whole-genome sequencing by NGS with targeted haplotyping was performed on biopsied trophectoderm cells. A healthy baby was born after transfer of a single freeze-thawed blastocyst.

CONCLUSIONS

The use of targeted NGS for identifying diagnostic markers combined with targeted haplotyping is an easy and efficient PGT-M method for preventing intergenerational transmission of AS.

Case Report: Preimplantation Genetic Testing and Pregnancy Outcomes in Women With Alport Syndrome

Background

Alport syndrome, a monogenic kidney disease, is characterized by progressive hemorrhagic nephritis, sensorineural hearing loss, and ocular abnormalities. Mutations in COL4A5 at Xq22 accounts for 80–85% of X-linked Alport syndrome patients. Three couples were referred to our reproductive genetics clinic for prenatal or preconception counseling.

Methods

Prenatal diagnoses were performed by amplifying targeted regions of COL4A5. Targeted next-generation sequencing (NGS)-based haplotype analysis or karyomapping was performed in two patients. Pregnancy outcomes in the three patients were collected and analyzed. Published Alport syndrome cases were searched in Pubmed and Embase.

Results

Prenatal diagnoses in two cases showed one fetus harbored the same pathogenic mutation as the proband and the other was healthy. The couple with an affected fetus and the patient with a family history of Alport syndrome chose to take the preimplantation genetic testing (PGT) procedure. One unaffected embryo was transferred to the uterus, and a singleton pregnancy was achieved, respectively. Two patients presented non-nephrotic range proteinuria (<3 g/24 h) during pregnancy and the three cases all delivered at full-term. However, published Alport cases with chronic kidney disease or proteinuria during pregnancy were came with a high rate (75%) of adverse maternal and fetal outcomes.

Conclusion

The PGT procedure performed in this study was proven to be practicable and might be expanded to be applied in other monogenic diseases. Moderate or severe renal impairments in Alport syndrome were strongly associated with adverse maternal and fetal outcomes, and baseline proteinuria was a potential predictor for pregnancy outcomes of Alport syndrome as other kidney diseases.

Renal impairment in Alport syndrome pregnant woman: Case report and review of the literature

Pregnant women affected by Alport syndrome often struggle with worsening of renal function during pregnancy. We focused the attention on the optimal management of the kidney disease in these women in order to avoid maternal-fetal complications.

Autosomal Recessive Alport Syndrome Unveiled by Pregnancy

Alport syndrome is a hereditary disease affecting Type IV collagen characterized by hematuria, progressive renal failure, sensorineural hearing loss, and ocular abnormalities. Most cases are X-linked and involve the COL4A5 gene with a minority of patients having autosomal recessive mutations in the COL4A3 or COL4A4 genes encoding the α3(IV) or α4(IV) chain respectively. Here, we describe the case of a 31-year-old woman who presented during pregnancy with hematuria and proteinuria and was diagnosed with autosomal recessive Alport syndrome (ARAS) post-partum. Her biopsy was notable for findings of segmental glomerulosclerosis with some collapsing features, in addition to thin basement membranes and rare "splitting". Genetic testing identified 2 novel mutations in the COL4A4 gene: a truncating frame shift mutation c.3861delinsCTC and a missense mutation c.4708G>A (p.Glu1570Lys), both of which we assert to be pathogenic. She had normal full-term delivery without complications. This case has several unique features including the relatively mild disease phenotype and the findings of glomerular scarring with collapsing features on renal biopsy. The successful pregnancy outcome and her clinical presentation add to the growing body of evidence that ARAS can have a variable phenotype.

Features of Autosomal Recessive Alport Syndrome: A Systematic Review

Alport syndrome (AS) is one of the most frequent hereditary nephritis leading to end-stage renal disease (ESRD). Although X-linked (XLAS) inheritance is the most common form, cases with autosomal recessive inheritance with mutations in COL4A3 or COL4A4 are being increasingly recognized. A systematic review was conducted on autosomal recessive Alport syndrome (ARAS). Electronic databases were searched using related terms (until Oct 10th, 2018). From 1601 articles searched, there were 26 eligible studies with 148 patients. Female and male patients were equally affected. About 62% of patients had ESRD, 64% had sensorineural hearing loss (SNHL) and 17% had ocular manifestation. The median at onset was 2.5 years for hematuria (HU), 21 years for ESRD, and 13 years for SNHL. Patients without missense mutations had more severe outcomes at earlier ages, while those who had one or two missense mutations had delayed onset and lower prevalence of extrarenal manifestations. Of 49 patients with kidney biopsy available for electron microscopy (EM) pathology, 42 (86%) had typical glomerular basement membrane (GBM) changes, while 5 (10%) patients showed GBM thinning only. SNHL developed earlier than previously reported. There was a genotype phenotype correlation according to the number of missense mutations. Patients with missense mutations had delayed onset of hematuria, ESRD, and SNHL and lower prevalence of extrarenal manifestations.

Twin pregnancy in a patient on chronic haemodialysis who already had three pregnancies

Pregnancy in women with end-stage renal disease is rare. Multiple pregnancies carry a high risk of complications even in healthy individuals. We report the case of a 36-year-old woman who had four pregnancies while she was on dialysis, including one twin pregnancy. The last pregnancy occurred while in the 14th year of hemodialysis. At 8 weeks of gestation (WG), ultrasonography diagnosed a dichorionic diamniotic twin pregnancy. The frequency of dialysis was increased from 3 to 6 times a week and each session lasted 4 h. At 22 WG, polyhydramnios was diagnosed. At 25 WG, the patient presented respiratory distress and was transferred to intensive care where continuous hemodialysis, non-invasive ventilation, antibiotic and tocolysis were initiated. Because of tocolysis failure, a cesarean section was performed and she delivered male twins. The two newborns weighed 790 and 870 g, respectively. To our knowledge, this is the first report of four pregnancies in hemodialysis including one twin pregnancy. The incidence of pregnancy and a better outcome in patients on hemodialysis has increased in recent years but a tight coordination between nephrologists and obstetricians is essential.

Alport syndrome and pregnancy: a case series and literature review

PURPOSE

To assess pregnancy outcome in women with Alport syndrome and the impact of pregnancy on the disease progression.

METHODS

We describe one of the largest series of pregnancies in Alport syndrome. Seven pregnancies of six women were monitored by a multidisciplinary team of nephrologists and gynecologists. After delivery, patients were followed for at least 3 years. We compare our results with those in the literature.

RESULTS

Pregnancy course was uneventful in the patient with isolated microscopic hematuria. In the other cases, all presenting mild proteinuria at conception, some complications occurred. Proteinuria worsened during the last trimester, reaching nephrotic ranges in five out of six pregnancies and was associated with fluid overload leading to hospitalizations and early delivery. The majority of the newborns had a low birth weight. The two patients with arterial hypertension at conception and twin pregnancy developed pre-eclampsia and renal function deterioration persisted after delivery. The one with pre-pregnancy renal dysfunction reached end-stage renal disease. In the other patients, in which renal function and blood pressure were and remained normal, proteinuria improved after delivery and no signs of disease progression were recorded at last observation.

CONCLUSIONS

Our observations suggest that Alport syndrome should be considered a potential risk factor for pregnancy in proteinuric patients due to the development of pre-eclampsia, renal function deterioration, and/or full-blown nephrotic syndrome that results in anasarca, slowing of fetal growth and pre-term delivery. Thus, all women with Alport syndrome should receive pre-conceptional counseling and be kept in close follow-up during pregnancy.

Two Pregnancies with a Different Outcome in a Patient with Alport Syndrome

BACKGROUND

Alport syndrome is a genetic disease that progresses to chronic kidney failure, with X-linked, autosomal dominant or autosomal recessive type of inheritance. Women are generally carriers of the mutation and have a milder form of the disease. During pregnancy, they have an increased risk of impaired kidney function and preeclampsia.

CASE PRESENTATION

A 27-year old woman, gravida 1, para 0, in her 23rd gestational week came to the outpatient unit of the University Clinic of Nephrology for the first time because of slowly progressing proteinuria and Alport syndrome. She was admitted to the gynaecological ward in her 29th gw for proteinuria which increased from 3.8 g/day up to 20 g/day and the serum creatinine increased to 120- 150 micromol/l. She was delivered in the 30th gestational week due to obstetrical indications with a cesarian section and delivered a baby with a birth weight of 880 g. After delivery, proteinuria decreased to 2 g/d within 2 months and an angiotensin-converting enzyme inhibitor (ACEI) was started. Her second pregnancy, after 2 years, had an uneventful course and she delivered a healthy baby weighing 3000 g in the 39th week. Six months after the second delivery, her renal function remained normal and her proteinuria was 2 g/d.

CONCLUSIONS

Pre-pregnancy counselling and frequent controls during pregnancy are necessary for women with Alport syndrome, as well as regular monitoring after delivery. Recent reports are more in favour of good pregnancy and nephrological outcomes in women with Alport syndrome when renal disease is not advanced.