Pterin Profiling in Serum, Dried Blood Spot, and Urine Samples Using LC-MS/MS in Patients with Inherited Hyperphenylalaninemia.

Background: Hyperphenylalaninemia (HPA) is defined as blood phenylalanine (Phe) levels exceeding the normal values (>120 µmol/L or >2 mg/dL) and is caused by a deficiency in the enzyme phenylalanine hydroxylase (PAH). The widespread screening of Phe levels in newborn screening programs has led to a very high number of patients with HPA. Methods: The samples were collected at various ages, not at the point of diagnosis. Nine pterin derivatives, including isoxanthopterin, sepiapterin, xanthopterin, primapterin, biopterin, neopterin, 7,8-dihydrobiopterin, 7,8-dihydroneopterin, and tetrahydrobiopterin (BH4), were analyzed in different HPA classes in serum, dried blood spots (DBS), and urine samples. A total of 18 patients, including six classical phenylketonuria (PKU), eight BH4-responsive PKU, and four mild HPA patients, were included in the study. Results: Among the nine pterin derivatives measured, a significant increase was observed in the levels of isoxanthopterin, biopterin, and 7,8-dihydrobiopterin in serum, dried blood spots (DBS), and urine samples of patients with HPA compared to the control group. However, elevations in isoxanthopterin, biopterin, and 7,8-dihydrobiopterin were observed in all HPA groups, although the extent of elevation varied among the different disease groups. There were also significant differences between HPA subgroups among these high values. Conclusion: In this study, it might be suggested that pterin profiling shows promising potential for its effective utilization in the differential diagnosis of HPA. Pterin profiling demonstrated its efficacy in accurately categorizing patients into distinct subtypes. This approach offers several notable advantages, including the ability to simultaneously screen multiple HPA subtypes through a single test, establish disease decision limits for pterins, shorten the time required for HPA differential diagnosis, reduce the risk of misdiagnosis, and increase overall diagnostic accuracy. This study is the most comprehensive study examining the association between HPA pterin in the literature. In our study, samples obtained from BH4-responsive PKU patients were on treatment. This may have affected the results. Preliminary findings on pterin profiles may need to be replicated in a prospective cohort of samples collected at the time of diagnosis to confirm the results.

Advances in Immune Tolerance Induction in Enzyme Replacement Therapy.

Inborn errors of metabolism (IEMs) are a group of genetic diseases that occur due to the either deficiency of an enzyme involved in a metabolic/biochemical pathway or other disturbances in the metabolic pathway including transport protein or activator protein deficiencies, cofactor deficiencies, organelle biogenesis, maturation or trafficking problems. These disorders are collectively significant due to their substantial impact on both the well-being and survival of affected individuals. In the quest for effective treatments, enzyme replacement therapy (ERT) has emerged as a viable strategy for patients with many of the lysosomal storage disorders (LSD) and enzyme substitution therapy in the rare form of the other inborn errors of metabolism including phenylketonuria and hypophosphatasia. However, a major challenge associated with enzyme infusion in patients with these disorders, mainly LSD, is the development of high antibody titres. Strategies focusing on immunomodulation have shown promise in inducing immune tolerance to ERT, leading to improved overall survival rates. The implementation of immunomodulation concurrent with ERT administration has also resulted in a decreased occurrence of IgG antibody development compared with cases treated solely with ERT. By incorporating the knowledge gained from current approaches and analysing the outcomes of immune tolerance induction (ITI) modalities from clinical and preclinical trials have demonstrated significant improvement in the efficacy of ERT. In this comprehensive review, the progress in ITI modalities is assessed, drawing insights from both clinical and preclinical trials. The focus is on evaluating the advancements in ITI within the context of IEM, specifically addressing LSDs managed through ERT.

Clinical characteristics of adult and paediatric patients with familial hypercholesterolemia: A real-life cross-sectional study from the Turkish National Database.

BACKGROUND AND AIMS: Familial hypercholesterolemia (FH) is the most common cause of premature atherosclerotic cardiovascular disease (ASCVD). Türkiye is among the countries with the highest rate of ASCVD. However, no population-based study has been published so far on the prevalence of FH, demographic and clinical characteristics, burden of ASCVD, treatment compliance, and attainment of low-density lipoprotein cholesterol (LDL-C) targets. METHODS: We performed a study using the Turkish Ministry of Health's national electronic health records involving 83,063,515 citizens as of December 2021 dating back 2016. Adults fulfilling the diagnostic criteria of definite or probable FH according to the Dutch Lipid Network Criteria (DLNC), and children and adolescents fulfilling the criteria of probable FH according to the European Atherosclerosis Society (EAS) Consensus Panel report formed the study population (n = 157,790). The primary endpoint was the prevalence of FH. RESULTS: Probable or definite FH was detected in 0.63% (1 in 158) of the adults and 0.61% (1 in 164) of the total population. The proportion of adults with LDL-C levels >4.9 mmol/L (190 mg/dL) was 4.56% (1 in 22). The prevalence of FH among children and adolescents was 0.37% (1 in 270). Less than one-third of the children and adolescents, and two-thirds of young adults (aged 18-29) with FH were already diagnosed with dyslipidaemia. The proportion of adults and children and adolescents on lipid-lowering treatment (LLT) was 32.1% and 1.5%, respectively. The overall discontinuation rate of LLT was 65.8% among adults and 77.9% among children and adolescents. Almost no subjects on LLT were found to attain the target LDL-C levels. CONCLUSIONS: This nationwide study showed a very high prevalence of FH in Türkiye. Patients with FH are diagnosed late and treated sub-optimally. Whether these findings may explain the high rates of premature ASCVD in Türkiye needs further investigation. These results denote the urgent need for country-wide initiatives for early diagnosis and effective management of FH patients.

Long-Term Experience with Anaphylaxis and Desensitization to Alglucosidase Alfa in Pompe Disease.

BACKGROUND AND OBJECTIVE: Pompe disease (PD) is an inherited lysosomal storage disease that progresses with glycogen accumulation in many tissues, due to the deficiency of the acid-alpha glucosidase enzyme. Recombinant alglucosidase alfa (rhGAA) is the only disease-specific treatment option, in the form of enzyme replacement therapy (ERT). Anaphylaxis can develop with rhGAA. There is no study evaluating anaphylaxis and its management in PD in the long term. We aimed to evaluate the development of anaphylaxis and rapid drug desensitization (RDD) with rhGAA in children with PD. MATERIALS AND METHODS: All children diagnosed and followed up in our institution with PD over 12 years between January 2009 and September 2021 were evaluated for development of anaphylaxis and RDD with rhGAA from medical records. RESULTS: Fourteen patients, 64% of whom were female and diagnosed with PD (1 juvenile, 13 infantile types) during the study period included in the study. The median age at diagnosis was 3.2 months (1-40 months). The median follow-up time of the patients was 20 months (1-129 months). Thirteen patients were given rhGAA, one died before ERT. Four (30.8%) patients developed moderate to severe anaphylaxis, and RDD was applied with rhGAA. A total of 390 RDDs have been performed so far without any serious breakthrough reactions during all RDDs. CONCLUSIONS: Anaphylaxis with rhGAA is not rare and RDD with rhGAA is safe and effective in the long term.

Expected or unexpected clinical findings in liver glycogen storage disease type IX: distinct clinical and molecular variability.

OBJECTIVES: To reveal the different clinical presentations of liver glycogen storage disease type IX (GSD IX), which is a clinically and genetically heterogeneous type of glycogenosis. METHODS: The data from the electronic hospital records of 25 patients diagnosed with liver GSD IX was reviewed. Symptoms, clinical findings, and laboratory and molecular analysis were assessed. RESULTS: Of the patients, 10 had complaints of short stature in the initial presentation additionally other clinical findings. Elevated serum transaminases were found in 20 patients, and hepatomegaly was found in 22 patients. Interestingly, three patients were referred due to neurodevelopmental delay and hypotonia, while one was referred for only autism. One patient who presented with neurodevelopmental delay developed hepatomegaly and elevated transaminases during the disease later on. Three of the patients had low hemoglobin A1C and fructosamine values that were near the lowest reference range. Two patients had left ventricular hypertrophy. Three patients developed osteopenia during follow-up, and one patient had osteoporosis after puberty. The most common gene variant, PHKA2, was observed in 16 patients, 10 variants were novel and six variants were defined before. Six patients had variants in PHKG2, two variants were not defined before and four variants were defined before. PHKB variants were found in three patients. One patient had two novel splice site mutations in trans position. It was revealed that one novel homozygous variant and one defined homozygous variant were found in PHKB. CONCLUSIONS: This study revealed that GSD IX may present with only hypotonia and neurodevelopmental delay without liver involvement in the early infantile period. It should be emphasized that although liver GSDIX is thought of as a benign disease, it might present with multisystemic involvement and patients should be screened with echocardiography, bone mineral densitometry, and psychometric evaluation.

Two patients from Turkey with a novel variant in the GM2A gene and review of the literature.

OBJECTIVES: GM2 gangliosidosis is a rare form of inborn errors of metabolism including Tay-Sachs disease, Sandhoff disease, and GM2 activator deficiency. GM2 activator protein deficiency is an ultra-rare form of GM2 gangliosidosis. To date, 16 cases of GM2 activator protein deficiency have been reported in the literature, and among them, 11 cases were the infantile form of the disease. Here we report the first two patients from Turkey with the infantile form of the disease with a novel likely pathogenic variant. CASE PRESENTATION: A boy of eight months old presented to the metabolic department with very mild neurological deterioration, although he had achieved early developmental milestones at the appropriate time. The parents also had a daughter who had lost skills progressively before one year of age. The boy was evaluated and bilateral cherry-red spots were found with no abnormality in either metabolic screening including ß-hexosaminidase or cranial magnetic resonance imaging. A novel homozygous likely pathogenic variant in GM2A was detected in a next-generation sequence panel revealing GM2 activator protein deficiency. His sister was investigated after he was diagnosed with GM2 activator deficiency and it was found that she had the same variant as her brother. CONCLUSIONS: This case report emphasizes that in the event of normal ß-hexosaminidase activity, GM2 activator protein deficiency could be underdiagnosed, and further molecular analysis should be performed. To the best of our knowledge, this boy is one of the youngest patient diagnosed with very mild symptoms. With this novel pathogenic variant, these patients have expanded the mutation spectrum of GM2 activator protein deficiency.

The first case with FBXL4 mutation successfully treated with a parenteral ketogenic diet for lactic acidosis.

BACKGROUND: The ketogenic diet (KD) is a low-carbohydrate, high-fat diet that has been used as an effective nonpharmacological treatment in many neurological and metabolic disorders for a long time. The effectiveness of the KD is revealed in mitochondrial disorders, mainly in pyruvate dehydrogenase deficiency. CASE REPORT: A 4-year-old girl who was diagnosed with an F-box and leucine-rich repeat protein 4 (FBXL4) gene mutation was hospitalized with sepsis. She was first given standard parenteral nutrition (PN) because of gastrointestinal problems. During the disease course, lactic acidosis became prominent and did not respond to pharmacological treatment; standard PN was gradually switched to parenteral KD, and lactate levels decreased after parenteral KD. The patient was discharged with an enteral KD. CONCLUSION: This is the first case of mitochondrial depletion syndrome effectively treated with parenteral KD for lactic acidosis.

Autism: Screening of inborn errors of metabolism and unexpected results.

In this study, the aim was to examine patients with inborn errors of metabolism (IEM) who presented with only autism, without any other findings, to suggest any other neurological and genetic disorders. To investigate IEM, data of the hospital records of 247 patients who were referred from pediatric psychiatric to pediatric metabolism outpatient clinics due to further evaluation of autism spectrum disorders (ASD) were examined. Among them, 237 patients were evaluated for IEM leading to ASDs. Organic acidemias, phenylketonuria, tetrahydrobiopterin and neutrotransmitter disorders, biotinidase deficiency, Smith-Lemni-Opitz syndrome, disorders of cerebral creatine metabolism, urea cycle defects, homocystinuria, purine-pyrimidine metabolism disorders, mitochondrial disorders, cerebrotendinous xantomatosis, mucopolysaccaridosis, and glucose 6 phosphate dehydrogenase deficiency were screened with complete blood counts, complete biochemical analyses, homocysteine levels, an arterial blood gase, and metabolic investigations. Six patients were diagnosed as follows: one with phenylketonuria (PKU), one with cerebral creatine deficiency, one with hypobetalipoproteinemia, one with glycogen storage disease type IX-a, one with dihydropyrimidine dehydrogenase deficiency, and one with succinic semialdehyde dehydrogenase deficiency (SSADHD). Forty-six patients screened for IEM were from consanguineous families, among them, one was diagnosed with FKU and the other was with SSADHD. It would not be expected to find PKU in a 5-year-old patient as a result of newborn screening, but she could not been screened due to being a refugee. The diagnosed diseases were rare presentations of the diseases and furthermore, the diagnosis of hypobetalipoproteinemia and glycogen storage disease type IX-a were surprising with the only presentation of ASDs. LAY SUMMARY: It is well-known that some types of inborn errors of metabolism (IEM) may present with that of autism spectrum disorders (ASDs). This study suggests that in countries where consanguinity marriages are common such as Turkey and refugees whose escaped from neonatal screening are present, patients with ASD should be screened for IEMs. The results can surprise the physicians with a very rare cause of autism that has never been thought. Autism Res 2021, 14: 887-896. © 2021 International Society for Autism Research, Wiley Periodicals LLC.

Hypophosphatasia: is it an underdiagnosed disease even by expert physicians?

INTRODUCTION: Hypophosphatasia (HPP) is caused by mutations in the ALPL that encodes the tissue-nonspecific isoenzyme of alkaline phosphatase (ALP). Clinical manifestations range from extreme life-threatening lethal forms to no signs or symptoms at all. MATERIALS AND METHODS: Consecutive 30,000 outpatients and inpatients with ALP data were screened retrospectively, out of which 1000 patients were found to have low levels of ALP more than once. Then, patients were evaluated for the symptoms and signs of HPP with further biochemical and genetic analyses. RESULTS: Thirty-seven patients who had severe musculoskeletal pain, recurrent fractures, and tooth anomalies were then screened with substrate and DNA sequencing analyses for HPP. It was determined that eight patients had variants in the ALPL gene. A total of eight different ALPL variants were identified in eight patients. The variants, namely c.244G > C (p.Gly82Arg), c.1444C > T (p.His482Tyr), c.1487A > G (p.Asn493Ser), and c.675_676insCA (p.Met226GlnfsTer52), had not been previously reported. DISCUSSION: Considering the wide spectrum of clinical signs and symptoms, HPP should be among the differential lists of bone, muscle, and tooth abnormalities at any age.

Beneficial Effects of Modified Atkins Diet in Glycogen Storage Disease Type IIIa.

INTRODUCTION: Glycogen storage disease Type III (GSD III) is an autosomal recessive disease caused by the deficiency of glycogen debranching enzyme, encoded by the AGL gene. Two clinical types of the disease are most prevalent: GSD IIIa involves the liver and muscle, whereas IIIb affects only the liver. The classical dietetic management of GSD IIIa involves prevention of fasting, frequent feeds with high complex carbohydrates in small children, and a low-carb-high-protein diet in older children and adults. Recently, diets containing high amount of fat, including ketogenic and modified Atkins diet (MAD), have been suggested to have favorable outcome in GSD IIIa. METHODS: Six patients, aged 3-31 years, with GSD IIIa received MAD for a duration of 3-7 months. Serum glucose, transaminases, creatine kinase (CK) levels, capillary ketone levels, and cardiac parameters were followed-up. RESULTS: In all patients, transaminase levels dropped in response to MAD. Decrease in CK levels were detected in 5 out of 6 patients. Hypoglycemia was evident in 2 patients but was resolved by adding uncooked cornstarch to diet. CONCLUSION: Our study demonstrates that GSD IIIa may benefit from MAD both clinically and biochemically.

Posterior fossa horns; a new calvarial finding of mucopolysaccharidoses with well-known cranial MRI features

Background/aim: Mucopolysaccharidoses (MPS) are a group of hereditary metabolic diseases. The aim of this study was to share the previously unreported calvarial finding of internal hypertrophy of the occipitomastoid sutures (IHOMS) together with some other well-known cranial MRI findings in this patient series. Materials and methods: A retrospective evaluation was conducted of 80 cranial MRIs of patients who had been diagnosed and followed up with MPS from 2008 to 2019 in our center. Of these patients, 11 had Hurler, 14 had Hunter, 24 had Sanfilippo, 15 had Morquio, 14 had Maroteaux­Lamy, and 2 had Sly disease. The cranial MRIs were assessed in two main groups as parenchymal intradural cranial MRI findings and extradural calvarial findings. Results: The most common parenchymal intradural cranial MRI findings were white matter signal alterations (n = 51, 63%) and perivascular space enlargements (n = 39, 48%). The most common extradural calvarial findings were J-shaped sella (n = 45, 56%) and tympanic effusion (n = 44, 55%). Although IHOMS was defined in a relatively small number of the patients (n = 12, 15%), the prevalence rate was high in MPS type I (n = 6, 54%). Conclusion: The abnormal cranial MRI findings of the MPS patients, including the newly identified IHOMS, may provide diagnostic clues to differentiate the type of the disease in radiological imaging.

A rare case of primary coenzyme Q10 deficiency due to COQ9 mutation.

Background Coenzyme Q10 (CoQ10) serves as a shuttle for electrons from complexes I and II to complex III in the respiratory chain, and has important functions within the mitochondria. Primary CoQ10 deficiency is a mitochondrial disorder which has devastating effects, and which may be partially treated with exogenous CoQ10 supplementation. Case presentation A 9-month-old girl patient was referred to our clinic due to growth retardation, microcephaly and seizures. She was the third child of consanguineous parents (first-degree cousins) of Pakistani origin, born at 38 weeks gestation, weighing 2000 g after an uncomplicated pregnancy, and was hospitalized for 3 days due to respiratory distress. She had sustained clonic seizures when she was 4 months old. Physical examination showed microcephaly, truncal hypotonia and dysmorphic features. Metabolic tests were inconclusive. Abdominal ultrasonography revealed cystic appearance of the kidneys. Non-compaction of the left ventricle was detected in echocardiography. Cranial magnetic resonance imaging (MRI) showed hypoplasia of the cerebellar vermis and brain stem, corpus callosum agenesis, and cortical atrophy. A panel testing of 450 genes involved in inborn errors of metabolism (IEM) was performed that showed a novel frameshift c.384delG (Gly129Valfs*17) homozygous mutation in COQ9. A treatment of 5 mg/kg/day exogenous CoQ10 was started when she was 10 months old, and the dosage was increased to 50 mg/kg/day after the exact diagnosis. No objective neurological improvement could be observed after the adjustment of the drug dosage. Conclusions We report a case of CoQ10 deficiency due to a novel COQ9 gene mutation that adds clinical data from a newly diagnosed patient. Our case also outlines the importance of genetic panels used for specific diseases including IEM.

Multicystic Dysplastic Kidney and Incontinentia Pigmenti: Coexistence of 2 Rare Diseases.

Multicystic dysplastic kidney is a congenital kidney malformation consisting of multiple cysts of various sizes without a normal kidney morphology. Incontinentia pigmenti is a rare X-linked dominant genodermatosis, which is usually lethal in males, that presents clinically in 4 stages. Here, we report a case of multicystic dysplastic kidney with ureterovesical junction obstruction and incontinentia pigmenti. Coexistence of these two rare diseases may be a coincidental phenomenon or an association between the two may exist.

The role of IFIH1 gene rs1990760 and rs2111485 single-nucleotide polymorphisms in generalized vitiligo predisposition

Background/aim: Interferon-induced helicase (IFIH1) is a gene locus that has been recently defined as a candidate for susceptibility to generalized vitiligo (GV). The objectives of this study were to assess the association of IFIH1 gene, rs2111485, and rs1990760 single-nucleotide polymorphisms (SNP) with susceptibility to GV and the autoimmune diseases accompanying GV. Materials and methods: We prospectively studied GV patients and frequency-matched healthy controls by age and sex. The genotypes of the participants were determined for rs1990760 and rs2111485 SNPs of IFIH1. Dominant, recessive, and additive models were evaluated for each SNP adjusted for age and sex. Results: The patients and their controls were observed to be in the Hardy­Weinberg equilibrium for SNP1 (2q24.2, rs1990760, IFIH1, T/C) and SNP2 (2q24.2, rs2111485, IFIH1, G/A), respectively (all P > 0.7). For SNP1, every T allel addition was significantly associated with 1.53 times protectiveness in terms of vitiligo risk (P = 0.033). As for SNP2, every G allel addition was associated with 1.42 times protectiveness, close to statistical significance (P = 0.100). Conclusions: We detected that for SNP1, each T allel and for SNP2, each G allel are protective in terms of vitiligo development. Hereby, we confirmed that IFIH1 gene locus has a role in GV susceptibility.

Early severe anemia as the first sign of cystic fibrosis.

UNLABELLED: Severe anemia is reported to occur rarely in patients with cystic fibrosis (CF). This study aimed to determine the factors associated with early severe anemia in infants with CF. This study included 231 infants with CF from 3 pediatric CF centers ten year period that were retrospectively reviewed in terms of severe anemia as the first sign of CF. Factors that could affect anemia, such as age, pancreatic insufficiency, mutations, vitamin A and E, and albumin level were evaluated. Clinical and laboratory findings in CF patients that presented with severe anemia and no respiratory symptoms were compared to those in CF patients that did not present with severe anemia. Severe anemia as the first sign of CF was noted in 17 of 231 patients. Patient age, prolonged PT/INR and the albumin level differed significantly between the 2 groups of patients (P < 0.001). Feeding pattern, pancreatic insufficiency, vitamin E and A levels, and the types of genetic mutations did not differ between the 2 groups. The mean hemoglobin level was 5.59 ± 0.21 g/dL and respiratory symptoms began a mean 6.3 months after diagnosis of CF in the anemia group. CONCLUSION: In early infancy severe anemia in the absence of respiratory symptoms can be the first sign of CF. CF should be considered in the differential diagnosis of severe anemia in infants. Anemia can occur several months before respiratory symptoms in patients with CF and may be caused due to several reasons. WHAT IS KNOWN: • Severe anemia as a first sign is reported to occur rarely in patients with cystic fibrosis. • Although anemia is well known in cystic fibrosis, factors that cause severe anemia are not known clearly. What is New: • This study shows the importance of severe anemia as the first sign of cystic fibrosis. • Anemia can occur several months before respiratory symptoms in patients with CF.

A Rare Cause of Lower Extremity Ulcers: Prolidase Deficiency.

Prolidase deficiency is an autosomal recessive disorder, which is associated with chronic skin ulcers, a characteristic facial appearance, mental retardation, and recurrent infections. This study describes 4 patients with recurrent leg ulcerations and abnormal facies who were first clinically suspected of prolidase deficiency and then biochemically confirmed. Two siblings and 2 other patients were admitted to our clinic at different times, and they had some common features such as chronic leg and foot ulcers recalcitrant to treatment, consanguineous parents, facial dysmorphism, mental retardation, and widespread telangiectasias. Physical examination and detection of low prolidase level in blood finally led us to the diagnose of ulcers secondary to prolidase deficiency. Prolidase deficiency is a rare genodermatosis and must be considered in the differential diagnosis of recurrent leg and foot ulcers that develop at an early age.

[Situs inversus of the fibula: medialized fibula]. / Fibulanin situs inversusu: Medialize fibula.

Congenital extremity anomalies are caused by pathological changes during the development process of the embryo. Exposure to toxins during 4-12 weeks of pregnancy may lead to extremity anomalies. In this article, we present a girl patient born as one of triplets at the 31st week and fifth day of pregnancy with meningomyelocele, Arnold-Chiari type 2 malformation, developmental dysplasia of the right hip, hypothyroidism, and lower extremity anomaly. Mother had a history of antenatal usage of sodium valproate. Radiographic examination of the lower extremity showed medial location of the fibula.

A novel mutation in the mitochondrial DNA cytochrome b gene (MTCYB) in a patient with Prader Willi syndrome.

In recent years, it has been suggested that defects in energy metabolism may accompany Prader Willi syndrome. Mutations in the mitochondrial cytochrome b gene have been commonly associated isolated mitochondrial myopathy and exercise intolerance, rarely with multisystem disorders. The authors describe a novel mutation (mt. 15209T>C) in mitochondrial cytochrome b gene in a 2-year-old girl with Prader-Willi syndrome with a clinical history of lactic acidosis attacks, renal sodium loss, hepatopathy, progressive cerebral atrophy, and sudden death. The authors suggest that atypical clinical findings in patients with Prader-Willi syndrome should direct the physician to search for a mitochondrial disease.

Radiologic findings of Patterson-Lowry rhizomelic dysplasia in two sisters.

We report two sisters who have a rare skeletal abnormality termed Patterson-Lowry rhizomelic dysplasia. The typical findings of these cases on bone survey are isolated shortening and proximal metaphyseal enlargement and cupping of the bilateral humeri. The elder sister also has coxa vara deformity and dysplastic proximal femoral epiphyses on both sides. The younger sister has normal hip joint bones bilaterally, but her proximal femoral epiphyses are smaller than normal. All other bones of the sisters are of normal size and configuration. Our patients are two siblings, and their parents are first degree relatives, suggesting autosomal-recessive (AR) inheritance. The present patients help us to understand the genetic relationships and skeletal variabilities of this rare entity.