Severe hereditary spherocytosis presenting with non-immune fetal hydrops

Snehal Mallakmir; Rashid Merchant; Nandkishor S Kabra; Javed Ahmed

doi:10.4103/ipcares.ipcares_170_22

CASE REPORT

Year : 2023 | Volume : 3 | Issue : 1 | Page : 27-30

Severe hereditary spherocytosis presenting with non-immune fetal hydrops

Snehal Mallakmir, Rashid Merchant, Nandkishor S Kabra, Javed Ahmed
Surya Multi Speciality Hospitals for Women and Children, Mumbai, Maharashtra, India

Date of Submission	11-Jul-2022
Date of Decision	13-Jan-2023
Date of Acceptance	30-Jan-2023
Date of Web Publication	27-Feb-2023

Correspondence Address:
Dr. Snehal Mallakmir
No. 1001, 1002, Sadguru Platinum, Sector - 28, Nerul, Navi Mumbai - 400 706, Maharashtra
India

Source of Support: None, Conflict of Interest: None

DOI: 10.4103/ipcares.ipcares_170_22

Abstract

Background: Hereditary spherocytosis (HS) is characterized by spherocytes on the peripheral smear and heterogeneous clinical presentation (mild, moderate, moderate/severe, and severe) depending upon the severity of hemolytic anemia, jaundice, and splenomegaly. The underlying cause is defects in various red blood cell membrane proteins due to pathogenic mutations. Genotype-phenotype correlation is known. Clinical Description: We report a consanguineous family with a healthy daughter, multiple pregnancy losses due to fetal hydrops, and the current daughter. She was diagnosed with fetal anemia at 22 weeks gestation, developed fetal hydrops, was born premature and developed respiratory distress, severe anemia, severe jaundice, and postnatal hemolysis. Management: The case was managed since intrauterine life till date by multispecialty coordination. Intrauterine transfusions were given during pregnancy. In the neonatal period, she received surfactant for respiratory distress syndrome, double volume exchange transfusion and phototherapy for the jaundice, and repeated blood transfusions for the hemolytic anemia, that is still continuing. Rational and sequential investigations were planned and a systematic approach used. She was diagnosed with severe HS due to a homozygous likely pathogenic variant in the SPTA1 gene (affecting formation of spectrin), and heterozygous variant of uncertain significance in the ANK1 gene (that encodes ankyrin). At 3 years she has transfusion dependent hemolytic anemia, moderate splenomegaly, and age appropriate growth and development. Conclusions: HS is a rare but manageable (albeit challenging) cause of nonimmune hydrops fetalis. Genetic diagnosis allows precise management and family counselling.

Keywords: Ankyrin, hemolytic anemia, spectrin, SPTA1 gene

How to cite this article:
Mallakmir S, Merchant R, Kabra NS, Ahmed J. Severe hereditary spherocytosis presenting with non-immune fetal hydrops. Indian Pediatr Case Rep 2023;3:27-30

How to cite this URL:
Mallakmir S, Merchant R, Kabra NS, Ahmed J. Severe hereditary spherocytosis presenting with non-immune fetal hydrops. Indian Pediatr Case Rep [serial online] 2023 [cited 2023 Mar 22];3:27-30. Available from: http://www.ipcares.org/text.asp?2023/3/1/27/370524

The typical red blood cell (RBC) membrane comprises of an outer lipid bilayer in which complex protein molecules are enmeshed, and an inner helical cytoskeleton composed of a meshwork of alpha and beta spectrin. This physiological configuration gives the RBC its characteristic biconcave shape and allows it to pass through all blood vessels without getting damaged.

Hereditary spherocytosis (HS) is a RBC membrane disorder characterized by spherocytes in the peripheral smear. The estimated prevalence is 1:2000 to 1:5000. There is marked heterogeneity in clinical manifestations. Four forms are recognized depending on the extent of severity. Individuals with mild HS (20%–30% affected individuals) may have very mild anemia or asymptomatic. Moderate HS (60%–70%) presents in childhood with anemia, jaundice, splenomegaly and occasionally gallstones. Those with moderate/severe HS (10%) have all the features of moderate HS, but also severe anemia. Severe HS (3%–5%) manifest with life-threatening transfusion dependent anemia, severe splenomegaly, jaundice, high risk of gallstones, and occasionally short stature, skeletal abnormalities, and delayed sexual development.

HS occurs when mutations lead to loss of key structural proteins that leads to loss of membrane and results in rigidity and a spherical shape. The RBC gets hemolysed while passing through the spleen. These molecular defects are found in ankyrin (most common), alpha and beta spectrin (common), and also band 3 and protein 4.2. The defects in β-spectrin and band 3 are autosomal dominant (AD) in inheritance, whereas those in ankyrin are both AD and autosomal recessive.

There are reports of genotype-phenotype correlation between the severity of clinical features of HS with the degree of deficiency of the membrane proteins resulting from various mutations.^[1] We report a case of fetal hydrops treated with intrauterine transfusions, who continued to have severe recurrent hemolytic anemia throughout infancy, was diagnosed with HS, and found to have a homozygous pathogenic variant in SPTA1 gene and heterozygous variant of uncertain significance in the ANK1 gene. We discuss the management of a neonate detected with nonimmune fetal hydrops (NIFH) and followed up till the age of 3 years that would not have been possible without smooth multispecialty coordination among the obstetricians, neonatologists, hematologists, clinical geneticists, and pediatricians.

Clinical Description

A premature baby girl born at 31 weeks gestation was delivered by elective caesarian section for fetal anemia and high risk pregnancy, after receiving two doses of antenatal steroids 48 h before delivery for enhancing lung maturity. The baby cried immediately after birth with a normal APGAR (Appearance, pulse, grimace, activity, respiration) score. The birth weight was 2 kg. The baby developed respiratory distress within a few minutes of delivery and was transferred to the neonatal intensive care unit in a transport incubator with oxygen on flow.

There was a significant history of second degree consanguinity, a bad obstetric history and a stormy course in the current pregnancy. Fetal hydrops had been detected at another centre in the 20 weeks anomaly fetal Ultrasonography (USG) and the patient was referred to us, a tertiary center, at 22 weeks for further management. We detected increased fetal middle cerebral artery flow at 22 weeks in an antenatal USG that was suggestive of fetal anemia. Congenital anomalies were excluded based on the USG as well as fetal echocardiography. A cord blood sample was procured by cordocentesis that showed hemoglobin of 2 g%, and the fetus received three intrauterine packed cell transfusions. Unfortunately, the sample was insufficient in amount to be processed for the etiology of the anemia.

The mother was 30-year-old and had an 8-year-old healthy daughter, two still births, two first trimester abortions and one medical termination of pregnancy (MTP) as shown in [Figure 1]. The still births were a male fetus of 8 months gestation and a female fetus of 7 months gestation. During both pregnancies, the antenatal ultrasonography (USG) had detected fetal hydrops, but no other congenital abnormalities. Other clinical and investigation details were not available. The two abortions between 6 and 8 weeks of pregnancy had not been investigated in detail. The MTP had been performed in view of severe fetal hydrops identified at 20 weeks of gestation with no congenital abnormalities detected. Neither details nor documents pertaining to medical workup undertaken for determining the underlying etiology of these losses, were available.

Figure 1: Pedigree drawing showing second degree consanguinity and previous losses. G1-8 months gestation, male, still birth with hydrops. G2-8-years-old normal living female child. G3 - Spontaneous first trimester abortion, unknown cause. G4 - Spontaneous first trimester abortion, unknown cause. G5-7 months gestation, female, still birth with hydrops. G6-20 weeks medical termination of pregnancy in view of hydrops no other anomalies. G7 - Current female proband

Click here to view

Management and outcome

At admission, the baby was received with saturation maintained on O₂, but with tachypnoea (respiratory rate 70/min) and chest retractions suggestive of severe respiratory distress, for which heated humidified high flow nasal cannula support was immediately provided. The heart rate was 160/min, all peripheral pulses were palpable, and the capillary filling time and temperature were normal. Anthropometric parameters were not taken because of the general condition, but there was no overt microcephaly.

The baby was pale, and had icterus involving the palms and soles, but no cyanosis. There were no dysmorphic features, rashes, or pedal edema. The cranium, anterior fontanelle, and spine appeared normal. Abdominal examination revealed mild hepatosplenomegaly (liver and spleen 3 and 1 cm below costal margin, respectively). The baby had vigorous cry and tone and was moving all limbs spontaneously. There was no clinical evidence of intrauterine haemorrhage. No other systemic abnormalities were noted.

At admission, surfactant was administered as per standard protocol for respiratory distress syndrome. The cord blood bilirubin was 5.5 mg/dl and haemoglobin (Hb) 9.8 g/dl. The mother's blood group was AB positive while the baby's blood Group was B positive. Direct and indirect coombs tests were negative. Based on the clinical phenotype of recurrent fetal hydrops (presumed to be nonimmune based on these test results), fetal and postnatal anemia, we considered the differential diagnoses of disorders known to cause hemolytuc anemia of fetal onset, and planned investigations accordingly (given blow).

Intensive phototherapy (PT) was initiated and the baby was given a packed RBC transfusion. The serum bilirubin reached 14 mg/dl by 24 h of life. The baby received two double volume exchange transfusions (DVET) at 24 and 36 h of life, after which intensive PT was continued (till day 22 of life). The respiratory distress resolved by the 2^nd day of admission. There Hb level fell again (that was not explainable by blood sampling). This was presumed to be due to the ongoing hemolysis, and packed RBC transfusions were repeated at 3 and 4 weeks of life.

The investigations for the various causes of NIFH were planned in such a way to allow sufficient interval between transfusions and sample collection. The initial peripheral blood smear revealed normocytic hypochromic RBC and the reticulocyte count was 1%. Hemoglobin electrophoresis was negative for hemoglobinopathies. Hemolytic anemia due to enzyme defects (Glucose 6 phosphate dehydrogenase and pyruvate kinase) were ruled out by normal levels. The bone marrow aspiration did not reveal any abnormalities. Screening tests for inborn errors of metabolism (aminoacidopathies, and fatty acid oxidation disorders) was negative. Enzyme assays for lysosomal storage diseases like Gaucher and Niemann Pick disease were within normal range. Work up for TORCH infections, parvovirus B19, and bacterial infections was negative. The infantantogram and USG abdomen were normal without evidence of skeletal anomalies. Both parents were asymptomatic and had normal hemogram, peripheral smear, and Hb electrophoresis studies.

One month after the last blood transfusion (4 weeks of life), the baby's and her parents blood samples were sent for eosin-5-maleimide (EMA) binding test, used for detecting membrane defects. This uses the mean channel fluorescence (MCF) dye that binds to amino acids in the RBC membrane protein and has a normal range of 900–1300. The MCF values of the baby and her father and mother were low; 607.5, 782.18 and 780.04, respectively. Sodium dodecylsulphate (SDS)-polyacrylamide gel electrophoresis (PAGE) study for qualitative assessment of the trans-membrane proteins showed 70% reduction in alpha spectrin protein and 30% reduction in ankyrin protein, favouring the possibility of HS (supplemenatry file), and thus, genetic testing was ordered. Whole Exome analysis by next generation sequencing of the baby revealed homozygous pathogenic SPTA1 c.2428C>T (p.Gln810Ter) (Transcript ID-ENST00000368147) variation consistent with AR HS Type 3 (OMIM #270970), confirming our diagnosis. In addition a heterozygous ANK1 (Transcript ID-ENST00000265709) c.1505A>A/G. (p.Asp502Gly) variation of uncertain significance was found. The Gln810Ter variant has not been reported in the 1000 genomes and ExAC databases and the in silico prediction of the variant is damaging by Mutation Taster 2. The parents did not give consent for their own genetic studies (Supplementary file)[Additional file 1].

The baby was followed up regularly in the paediatrics department. She is now 3-year-old, has transfusion dependent hemolytic anemia (requiring monthly blood transfusions to maintain the recommended Hb levels), moderate splenomegaly, but has age appropriate normal growth and development.

Discussion

NIFH accounts for almost 90% cases of hydrops fetalis. Common causes are cardiovascular anomalies, chromosomal aneuploidies, hematological diseases (including hemolytic anemias), congenital infections, certain inborn errors of metabolism, lethal skeletal dysplasias, fetal tumours, placental abnormalities and single gene disorders.^[2] In view of increasing possibilities of precise confirmation of genetic etiologies and new emerging therapies, each one of these causes should be carefully evaluated clinically and investigated if suspected.

HS may cause hemolytic anemia and hyperbilirubinemia sufficiently severe to require exchange transfusions in neonates. Hemolysis is more prominent in the newborn because hemoglobin F binds 2,3-diphosphoglycerate poorly and the increased level of free 2,3-diphosphoglycerate destabilizes interactions among spectrin, actin, and protein 4.1 in the RBC membrane. In this case, absence of spherocytes and the characteristic elevated reticulocyte count was probably due to repeated intrauterine transfusions resulting in transient bone marrow suppression. Investigation results in babies who have required in-utero transfusions, DVET, and postnatal transfusions, need careful interpretation. Nonetheless, the clinical phenotype and preliminary investigations directed us towards hemolytic anemia due to a membrane defect. This was the reason for undertaking the EMA binding test that uses flow cytometry to determine the amount of fluorescence of RBCs reflecting EMA bound to the specific trans-membrane proteins. It is recommended by the International Council for Standardization in Hematology guidelines as a reliable screening test for RBC membranopathies.^[3]

The spectrin levels in patients with the AD form of HS are 63%–81% normal, generally resulting in mild anemia.^[4],[5] When patients manifest with severe disease, the anemia can range from severe to mild, with corresponding spectrin levels of 30%–74%.^[4],[5] The underlying HS can either be AR (homozygosity or compound heterozygosity for alpha spectrin mutation) or due to de novo mutation of ankyrin or beta spectin genes.^[4] The quantity of different membrane proteins is assessed by SDS-PAGE, followed by confirmation using just write exome sequencing (WES). This baby had a pathogenic mutation in both SPTA alleles causing 70% reduction in alpha spectrin and 30% reduction in ankyrin.

Various factors affect disease severity. Chonat et al. have discussed genotype phenotype correlation and gene expression in alpha spectrin deficiency.^[5] Common complications include cholelithiasis, hemolytic episodes and aplastic crises. These need to be carefully monitored. Though the child is doing well in terms of growth and development, she is transfusion dependent and has moderate splenomegaly. The next step in clinical management will be to decide upon partial or complete splenectomy.^[6] The main goal of presenting this case was to highlight the fact that even the most challenging of cases can have positive outcomes with multi-disciplinary collaboration and a systematic approach.

Acknowledgement

We acknowledge Dr. Prabhakar Kedar, Ms. Tejashree More, Dr. Prashant Warang and Dr. Manisha Madkaikar (from National Institute of Immunohaematology (ICMR), 13^th Floor, NMS Building, KEM Hospital Campus, Parel, Mumbai) for hematological studies and SDS PAGE analysis.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given her consent for her images and other clinical information to be reported in the journal. The patient understand that name and initials will not be published and due efforts will be made to conceal identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

References

1.	He BJ, Liao L, Deng ZF, et al. Molecular genetic mechanisms of hereditary spherocytosis: Current perspectives. Acta Haematol 2018;139:60-6.
2.	Bellini C, Hennekam RC, Fulcheri E, et al. Etiology of nonimmune hydrops fetalis: A systematic review. Am J Med Genet A 2009;149A: 844-51.
3.	King MJ, Garçon L, Hoyer JD, et al. ICSH guidelines for the laboratory diagnosis of nonimmune hereditary red cell membrane disorders. Int J Lab Hematol 2015;37:304-25.
4.	Eber SW, Armbrust R, Schröter W. Variable clinical severity of hereditary spherocytosis: Relation to erythrocytic spectrin concentration, osmotic fragility, and autohemolysis. J Pediatr 1990;117:409-16.
5.	Chonat S, Risinger M, Sakthivel H, et al. The spectrum of SPTA1-associated hereditary spherocytosis. Front Physiol 2019;10:815.
6.	Tole S, Dhir P, Pugi J, et al. Genotype-phenotype correlation in children with hereditary spherocytosis. Br J Haematol 2020;191:486-96.