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PubMed This is a summary of 17 peer-reviewed journal articles Updated
Hematology

Physical Features and the DBA Spectrum

At a Glance

Diamond-Blackfan anemia can cause anemia along with thumb, facial, heart, kidney, or growth differences, but many people have no physical anomalies. Genetic variants show broad population patterns, not reliable predictions for one child’s severity or treatment.

Diamond-Blackfan Anemia (DBA) is a condition that varies significantly from one person to another. While the core issue is a struggle to produce red blood cells, this “ribosome factory” problem can also affect how a baby’s body develops before birth [1]. Approximately 30% to 50% of children with DBA are born with one or more physical differences, though some studies suggest the number may be higher when specialists look very closely at features like heart or kidney structure [2][3].

It is important to remember that the absence of physical differences does not rule out DBA. Many children with DBA have no external physical anomalies at all [4].

Common Physical Findings

When physical anomalies do occur, they usually fall into a few specific categories:

  • Craniofacial Features: These are differences in the head and face. Common examples include a small lower jaw (micrognathia), a high-arched or cleft palate, wide-set eyes (hypertelorism), or low-set ears [3][5]. A short or webbed neck is also frequently reported [6].
  • Hand and Thumb Anomalies: The thumbs are uniquely sensitive to the developmental changes in DBA. A child might have a thumb that is smaller than usual (hypoplastic), lacks a joint, is positioned unusually, or is missing entirely [7]. In some cases, the radius (one of the bones in the forearm) may also be shortened [8].
  • Heart and Kidney Issues: Some children are born with “holes” in the heart (such as an atrial septal defect) or variations in how the kidneys or urinary tract are shaped [9][10].
  • Short Stature: Growth impairment is very common in DBA. About 38% of patients are significantly shorter than their peers [11]. This can be due to the disease itself, though it can also be influenced later by treatments like steroids [12].

The Role of Genetics (Genotype-Phenotype)

While we cannot predict exactly how DBA will affect an individual child, researchers have noticed patterns linked to specific genes. Important Warning: These are population-level associations with substantial overlap. A specific genetic variant cannot reliably determine an individual child’s treatment response, cancer risk, or severity. A dysmorphologist (a specialist in physical birth differences) can help assess your child.

Affected Gene Common Patterns and Associations
RPS19 The most common mutation. Children with this mutation often have the fewest physical birth defects but may be more likely to require long-term treatment for anemia [9].
RPL5 This gene is more frequently associated with a higher number of physical anomalies, particularly cleft lip or palate and heart defects [2][9].
RPL11 This mutation is specifically linked to thumb and hand abnormalities. Interestingly, these children may be less likely to need chronic, long-term anemia treatment compared to those with other mutations [7][9].

The Spectrum: Classic vs. Non-Canonical DBA

DBA is not a “one-size-fits-all” diagnosis. It exists on a spectrum that ranges from severe to nearly silent.

Classic DBA

The vast majority of children (around 90%) are diagnosed in infancy or early childhood with “classic” features: severe anemia, large red blood cells (macrocytosis), and a lack of new red blood cell production [13].

Non-Canonical and Adult-Onset DBA

“Non-canonical” refers to presentations that don’t follow the classic rules. Some people have a mutation for DBA but only have very mild anemia or even normal blood counts—this is sometimes called “silent” or non-penetrant DBA (meaning the gene is there but the trait is barely visible) [13][14].

Sometimes, an adult is only diagnosed after their child or grandchild is found to have the condition. These adults might have had mild, unexplained anemia for years, or they might have only physical signs (like a thumb difference) without ever being anemic [2][15]. In some rare cases, severe anemia doesn’t appear until adulthood, which can lead to it being misdiagnosed as other blood disorders initially [16][17].

Because of this “variable expression,” the same genetic “typo” can cause severe disease in a baby but almost no symptoms in that baby’s parent [15]. This is why genetic testing for parents is often recommended even if they feel perfectly healthy.

Common questions in this guide

What physical differences can occur with Diamond-Blackfan anemia?
Diamond-Blackfan anemia can be associated with thumb or forearm differences, facial or palate differences, heart or kidney abnormalities, and shorter stature. The specific combination varies widely from person to person.
Can someone have DBA without visible birth differences?
Yes. Many children with Diamond-Blackfan anemia have no obvious physical anomalies, and some internal heart or kidney differences may not be visible. A normal appearance does not rule out DBA.
Can a DBA gene variant predict how severe my child’s condition will be?
Genes such as RPS19, RPL5, and RPL11 show associations with certain physical findings across groups of patients. These patterns overlap substantially, so a specific variant cannot reliably predict one child’s anemia severity, treatment response, or cancer risk.
Why might healthy relatives need testing for a DBA mutation?
DBA can have variable expression, meaning a person may carry a family variant with mild anemia, normal blood counts, or only a physical feature such as a thumb difference. Testing relatives can clarify who carries the family variant and may need medical evaluation.
What evaluations may be considered for a child with DBA physical features?
A clinical geneticist or dysmorphologist can assess physical findings in detail. Depending on the child’s history and examination, the care team may consider heart imaging such as an echocardiogram, kidney imaging such as a renal ultrasound, and monitoring of height and weight; a pediatric endocrinologist may help with growth concerns.
What does non-canonical or adult-onset DBA mean?
Non-canonical DBA describes a less typical presentation, such as mild anemia, normal blood counts despite a DBA-associated variant, or physical findings without anemia. Some adults are diagnosed after a child or grandchild is found to have DBA, and rare cases develop severe anemia later in life.

Questions to Ask Your Doctor

Curated prompts to bring to your next appointment.

  1. 1.Has my child been evaluated by a clinical geneticist or dysmorphologist for a full assessment of physical features?
  2. 2.Since many features are internal, such as heart or kidney issues, should we perform an echocardiogram or renal ultrasound?
  3. 3.How does my child's specific genetic mutation (e.g., RPS19 vs. RPL5) correlate broadly with the physical findings we are seeing?
  4. 4.Does my child's current height and weight follow the expected growth trajectory for DBA, and should we consult a pediatric endocrinologist?
  5. 5.If we have relatives who were never diagnosed with anemia but have thumb differences, should they also be tested for the family's DBA mutation?

Questions For You

Tap a prompt to share your answer — we'll use it plus this page's context to start a tailored conversation.

References

References (17)
  1. 1

    Immunodeficiency in children with Diamond Blackfan and Diamond Blackfan like anemia.

    Ragab I, Makkeyah S, Hassan N, et al.

    Blood cells, molecules & diseases 2025; (111()):102911 doi:10.1016/j.bcmd.2025.102911.

    PMID: 39923319
  2. 2

    Familial RPL26 Variant Causing Congenital Anomalies Without Hematological Features of Diamond Blackfan Anemia.

    Karger LM, Webb BD, Edelmann L, et al.

    American journal of medical genetics. Part A 2025; (197(5)):e63954 doi:10.1002/ajmg.a.63954.

    PMID: 39710607
  3. 3

    Associated Congenital Abnormalities and Physical Phenotype in Patients with Diamond-Blackfan Anemia May Be Overlooked.

    Soltanova G, Avcu Oral N, Gümrük F, et al.

    Turkish archives of pediatrics 2024; (59(4)):364-369 doi:10.5152/TurkArchPediatr.2024.23193.

    PMID: 39110150
  4. 4

    Erythrocyte glutathione is a novel biomarker of Diamond-Blackfan anemia.

    Utsugisawa T, Uchiyama T, Toki T, et al.

    Blood cells, molecules & diseases 2016; (59()):31-6.

    PMID: 27282564
  5. 5

    Diagnosis and treatment of Diamond-Blackfan anemia and Pierre-Robin sequence caused by a novel mutation of RPS28 gene.

    Lin S, Hou L, Li X, et al.

    Hematology (Amsterdam, Netherlands) 2025; (30(1)):2481688 doi:10.1080/16078454.2025.2481688.

    PMID: 40135709
  6. 6

    Diagnostic challenge of Diamond-Blackfan anemia in mothers and children by whole-exome sequencing.

    Ichimura T, Yoshida K, Okuno Y, et al.

    International journal of hematology 2017; (105(4)):515-520 doi:10.1007/s12185-016-2151-7.

    PMID: 27882484
  7. 7

    Variable expressivity and incomplete penetrance in a large family with non-classical Diamond-Blackfan anemia associated with ribosomal protein L11 splicing variant.

    Carlston CM, Afify ZA, Palumbos JC, et al.

    American journal of medical genetics. Part A 2017; (173(10)):2622-2627 doi:10.1002/ajmg.a.38360.

    PMID: 28742285
  8. 8

    RPL26 variants: A rare cause of Diamond-Blackfan anemia syndrome with multiple congenital anomalies at the forefront.

    Vanlerberghe C, Frénois F, Smol T, et al.

    Genetics in medicine : official journal of the American College of Medical Genetics 2024; (26(12)):101266 doi:10.1016/j.gim.2024.101266.

    PMID: 39268718
  9. 9

    Molecular analysis and genotype-phenotype correlation of Diamond-Blackfan anemia.

    Arbiv OA, Cuvelier G, Klaassen RJ, et al.

    Clinical genetics 2018; (93(2)):320-328 doi:10.1111/cge.13158.

    PMID: 29044489
  10. 10

    [Diagnostic targets and exosome sequence analysis of Diamond-Blackfan anemia in Japan].

    Toki T, Ito E

    [Rinsho ketsueki] The Japanese journal of clinical hematology 2018; (59(7)):945-952 doi:10.11406/rinketsu.59.945.

    PMID: 30078807
  11. 11

    Short Stature in Patients with Diamond-Blackfan Anemia: A Cross-Sectional Study.

    Wan Y, Gong X, Cheng S, et al.

    The Journal of pediatrics 2022; (240()):177-185 doi:10.1016/j.jpeds.2021.09.015.

    PMID: 34543620
  12. 12

    Diamond-Blackfan anemia RPL35A: a case report.

    Noel CB

    Journal of medical case reports 2019; (13(1)):185 doi:10.1186/s13256-019-2127-3.

    PMID: 31208452
  13. 13

    An update on the pathogenesis and diagnosis of Diamond-Blackfan anemia.

    Da Costa L, Narla A, Mohandas N

    F1000Research 2018; (7()) doi:10.12688/f1000research.15542.1.

    PMID: 30228860
  14. 14

    Diamond Blackfan Anemia: A Nonclassical Patient With Diagnosis Assisted by Genomic Analysis.

    Steinberg-Shemer O, Keel S, Dgany O, et al.

    Journal of pediatric hematology/oncology 2016; (38(7)):e260-2 doi:10.1097/MPH.0000000000000587.

    PMID: 27258031
  15. 15

    Variable Clinical Features in a Large Family With Diamond Blackfan Anemia Caused by a Pathogenic Missense Mutation in RPS19.

    Cole S, Giri N, Alter BP, Gianferante DM

    Frontiers in genetics 2022; (13()):914141 doi:10.3389/fgene.2022.914141.

    PMID: 35923690
  16. 16

    Diagnosis of Diamond-Blackfan anemia in adulthood: case series and review of the literature.

    Versino F, Bianchi P, Fermo E, et al.

    Orphanet journal of rare diseases 2024; (19(1)):470 doi:10.1186/s13023-024-03490-6.

    PMID: 39702189
  17. 17

    A De Novo Frameshift Mutation in RPL5 with Classical Phenotype Abnormalities and Worsening Anemia Diagnosed in a Young Adult-A Case Report and Review of the Literature.

    Dorenkamp M, Porret N, Diepold M, Rovó A

    Medicina (Kaunas, Lithuania) 2023; (59(11)) doi:10.3390/medicina59111953.

    PMID: 38004002

This page is for informational purposes only and does not constitute medical advice. A hematologist and clinical geneticist should interpret your child’s physical findings, genetic results, and need for testing.

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